JP2010153140A - Non-aqueous electrolyte secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-aqueous electrolyte secondary battery capable of preventing deterioration of battery output and suppressing shortage of electrolytic solution. <P>SOLUTION: The non-aqueous electrolyte secondary battery has a power generation element having a unit battery layer in which a negative electrode forming a negative electrode active material layer containing a negative electrode active material on the surface of a current collector including a conductive layer 25, an electrolyte layer containing a nonaqueous electrolyte, and a positive electrode forming a positive electrode active material layer containing a positive electrode active material on the surface of a current collector including the conductive layer 25 are laminated in order. At least one of the current collectors included in the power generation element is an electrolytic solution retaining current collector which further includes an electrolytic solution retaining portion 26 for retaining the electrolytic solution. Furthermore, at least one of the conductive layers 25 has holes 29 in which the electrolytic solution can penetrate in lamination direction of the current collectors in the conductive substrate 28. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a non-aqueous electrolyte secondary battery. More specifically, the present invention relates to a nonaqueous electrolyte secondary battery having excellent capacity characteristics and output characteristics.

  In recent years, in order to cope with global warming, reduction of the amount of carbon dioxide is eagerly desired. In the automobile industry, there is a great expectation for reducing carbon dioxide emissions by introducing electric vehicles (EV) and hybrid electric vehicles (HEV), and the development of secondary batteries for motor drive that holds the key to commercialization of these is thriving. Has been done.

  As a secondary battery for driving a motor, it is required to have extremely high output characteristics and high energy as compared with a consumer lithium ion secondary battery used in a mobile phone, a notebook personal computer or the like. Therefore, lithium ion secondary batteries having the highest theoretical energy among all the batteries are attracting attention, and are currently being developed rapidly.

  Generally, a lithium ion secondary battery includes a positive electrode in which a positive electrode active material or the like is applied to both surfaces of a positive electrode current collector using a binder, and a negative electrode in which a negative electrode active material or the like is applied to both surfaces of a negative electrode current collector using a binder. However, it has the structure connected through an electrolyte layer and accommodated in a battery case.

Conventionally, carbon / graphite-based materials that are advantageous in terms of charge / discharge cycle life and cost have been used for negative electrodes of lithium ion secondary batteries. However, in a carbon / graphite negative electrode material, charging / discharging is performed by insertion / extraction of lithium ions into / from graphite crystals. As a result, there is a drawback that a charge / discharge capacity of a theoretical capacity of 372 mAh / g or more obtained from LiC ₆ which is the maximum lithium introduction compound cannot be obtained. For this reason, it is expected that it is difficult to obtain a capacity and energy density that satisfy the practical use level of the vehicle application with the carbon / graphite negative electrode material.

On the other hand, a battery using a material alloyed with lithium as a negative electrode active material is expected to be used as a negative electrode material for vehicles because the energy density is improved as compared with a conventional carbon / graphite negative electrode material. For example, the Si material occludes and releases 4.4 mol of lithium ions per mol as shown in the following reaction formula in charge and discharge, and Li ₂₂ Si ₅ has a theoretical capacity of about 2000 mAh / g.

  However, a lithium ion secondary battery using a material that forms an alloy with lithium as a negative electrode active material has a large negative electrode expansion and contraction during charge and discharge. For example, the volume expansion when lithium ions are occluded is about 1.2 times that of graphite, but about 4 times that of Si material. For this reason, voids are easily generated in the electrode layer due to the expansion of the electrodes, and as a result, there is a drawback that the electrolyte solution between the electrodes is insufficient, and the capacity of charge / discharge is likely to decrease.

As a method for making up for the lack of electrolyte during charging and discharging, a method for making up for the lack of electrolyte in the negative electrode due to swelling of the positive and negative electrodes by forming an electrolyte absorption layer between the negative electrode and the separator is disclosed. (See Patent Document 1).
JP-A-63-143743

  However, in the battery described in Patent Document 1, since the electrolyte solution absorbing layer is disposed between the positive electrode and the negative electrode, the distance between the electrodes increases. As a result, the shortage of the electrolyte during charging / discharging can be suppressed, but there is a problem that the output of the battery decreases.

  Therefore, an object of the present invention is to provide means capable of preventing a decrease in battery output and suppressing a shortage of electrolyte.

  The present inventors have intensively studied to solve the above problems. As a result, it has been found that the above problem can be solved by installing an electrolyte holding part for replenishing the electrolyte other than between the electrodes in the power generation element, and the present invention has been completed. It was.

  That is, the nonaqueous electrolyte secondary battery of the present invention includes a negative electrode in which a negative electrode active material layer containing a negative electrode active material is formed on the surface of a current collector containing a conductive layer, an electrolyte layer containing a nonaqueous electrolyte, A power generation element having a single battery layer in which a positive electrode formed by forming a positive electrode active material layer including a positive electrode active material on a surface of a current collector including a conductive layer is sequentially included. At least one of the current collectors included in the power generation element is an electrolyte solution holding current collector that further includes an electrolyte solution holding unit that holds the electrolyte solution.

  According to the present invention, the electrolyte can be supplied to the electrodes without increasing the distance between the electrodes from the electrolyte holding part of the current collector. Therefore, the shortage of the electrolyte due to the expansion and contraction of the electrode during charging and discharging can be suppressed, and the output characteristics of the battery can be maintained.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The technical scope of the present invention should be determined based on the description of the scope of claims, and is not limited to the following modes. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios.

[Stacked battery]
One embodiment of the present invention is a laminated nonaqueous electrolyte secondary battery (hereinafter also referred to as “laminated battery”).

  The stacked battery includes a positive electrode including a positive electrode active material layer electrically coupled to both surfaces of one current collector, and a negative electrode including a negative electrode active material layer electrically coupled to both surfaces of another current collector. The electrolyte layer disposed between the positive electrode and the negative electrode is alternately laminated.

  FIG. 1 is a schematic cross-sectional view showing a laminated nonaqueous electrolyte secondary battery which is a typical embodiment of the present invention. Hereinafter, the laminated battery shown in FIG. 1 will be described in detail as an example, but the technical scope of the present invention is not limited to such a form. For example, the battery of the present invention may be a bipolar non-aqueous electrolyte secondary battery.

  The stacked battery 10 of this embodiment shown in FIG. 1 has a structure in which a substantially rectangular power generation element 17 in which a charge / discharge reaction actually proceeds is sealed inside a laminate sheet 22 that is an exterior.

  As shown in FIG. 1, the power generation element 17 of the stacked battery 10 of this embodiment includes a single battery layer (= battery unit or single cell) 16. The single battery layer 16 includes a positive electrode 24 in which the positive electrode active material layer 15 is formed on the surface of the positive electrode current collector 14, an electrolyte layer 13, and a negative electrode active material layer 12 formed on the surface of the negative electrode current collector 11. And a negative electrode 23 formed in this order. In the laminated structure of the unit cell layers 16, one surface of the electrolyte layer 13 is in contact with the negative electrode active material layer 12, and the other surface of the electrolyte layer 13 is in contact with the positive electrode active material layer 15.

  The current collector (the positive electrode current collector 14 and the negative electrode current collector 11) used in the present embodiment includes a conductive layer. At least one of the positive electrode current collector 14 and the negative electrode current collector 11 included in the power generation element 17 has a configuration including an electrolyte solution holding portion in addition to the conductive layer (hereinafter, a current collector having such a configuration). The body is also referred to as “electrolyte holding current collector”).

  Further, as shown in FIG. 1, the conductive layers in the positive electrode current collector 14 and the negative electrode current collector 11 are collected at the end of the power generation element 17 and are ultrasonically welded through the positive electrode lead 21 and the negative electrode lead 20, respectively. Thus, the positive electrode tab 19 and the negative electrode tab 18 are electrically connected. The power generation element 17 is sealed with a laminate sheet 22 as an exterior so that the positive electrode tab 19 and the negative electrode tab 18 are led out of the laminate sheet 22 for the purpose of taking out electric power to the outside.

  In the stacked battery 10 shown in FIG. 1, the negative electrode active material layer 12 is slightly larger than the positive electrode active material layer 15, but is not limited to such a form.

  Hereinafter, although the member which comprises the laminated battery 10 of this embodiment is demonstrated, it is not restrict | limited only to the following form, A conventionally well-known form may be employ | adopted similarly.

[Current collector]
(Current collector structure)
The current collector (the positive electrode current collector and the negative electrode current collector) includes a conductive layer. In the current collector, the positive electrode active material layer and the negative electrode active material layer are electrically connected via the conductive layer, and power can be taken out to the outside. In the battery of the present invention, at least one of the current collectors (positive electrode current collector and negative electrode current collector) included in the power generation element includes an electrolyte solution holding portion in addition to the conductive layer (electrolyte solution holding current collector). Electric body). On the other hand, the current collector other than the above form may be in a form not including the electrolytic solution holding part (hereinafter also referred to as “electrolytic solution non-retaining current collector”). That is, in the non-aqueous electrolyte secondary battery of the present invention, all of the current collector may be an electrolyte holding current collector, or a part of the current collector is an electrolyte holding current collector. The other current collector may be an electrolyte non-holding current collector.

  The structure of the electrolytic solution holding current collector may have a multilayer structure in which a conductive layer and an electrolytic solution holding unit are laminated, or an integrated type in which an electrolytic solution holding unit is formed inside the conductive layer. It may have a single layer structure. Note that the electrolyte solution holding unit and the conductive layer do not necessarily have to be in contact with each other, and as long as the electrolyte solution can be supplied and supplied from the electrolyte solution holding unit, the electrolyte solution holding unit and the conductive layer are disposed between the electrolyte solution holding unit and the conductive layer. Voids or other layers may be included. However, it preferably has a configuration in which the electrolytic solution holding portion and the power generation element are in contact with each other. In such a form, the interface resistance between the electrolytic solution holding part and the conductive layer can be reduced, and thereby the output of the battery can be prevented from being lowered. In addition, the form in which the electrolytic solution holding part and the conductive layer are in contact with each other is not limited as long as the electrolytic solution holding part can be in contact with the conductive layer when the electrode is expanded. The portion need not be in physical contact with the conductive layer.

  FIG. 2 is a schematic cross-sectional view (schematic cross-sectional view in a plane parallel to the stacking direction of the power generation elements) of the electrolyte solution holding current collector used in a typical embodiment of the present invention. As shown in FIG. 2, the electrolyte solution holding current collector of the present embodiment is a multilayered laminate in which an electrolyte solution holding unit 26 is sandwiched between two conductive layers 25. Such an electrolyte solution holding current collector can be easily produced by laminating a conductive layer and an electrolyte solution holding part. In the conductive layer 25 of the present embodiment, a plurality of through holes 29 are formed in the conductive base material 28.

  3A and 3B are schematic cross-sectional views (schematic cross-sectional views in a plane parallel to and perpendicular to the stacking direction of the power generation elements) of the electrolyte solution holding current collector used in another embodiment of the present invention. The electrolyte solution holding current collector of the embodiment shown in FIGS. 3A and 3B is an integrated type in which an electrolyte solution holding part 26 is formed in the conductive layer 25.

  Such an integrated electrolyte solution holding current collector supplies the electrolyte solution to the outside of the electrolyte solution holding unit, so that the electrolyte solution holding unit 26 formed in the conductive layer 25 is formed on the surface of the conductive layer 25. It is necessary to have the opening 27. However, the electrolytic solution holding part only needs to have at least one such opening on one surface of the conductive layer, and does not need to have openings on both sides of the conductive layer.

  In the case of a laminated battery, it is preferable to have such openings on both sides of the conductive layer from the viewpoint of uniform supply and demand of the electrolyte. However, in the bipolar battery described later, when there are openings for the electrolyte solution holding part on both sides of the conductive layer, an electrode reaction occurs in the current collector and it cannot function as a bipolar battery. . For this reason, in the case of a bipolar battery, it is necessary to have an opening only on one surface of the conductive layer.

  In the present invention, the electrolyte solution holding current collector is preferably present in the central layer in the power generation element. In the present invention, the “central layer” means a layer located at the center in the stacking direction of the power generation elements in the power generation element having a stacked structure in which a plurality of single battery layers are stacked. Here, the layer located in the central portion includes not only a layer arranged at the center position in the stacking direction of the stacked structure but also a plurality of layers adjacent to the center layer. More specifically, it means a layer located at a position in the range of 30% to 70% from the top of the stack in the stacking direction of the power generation elements.

  The central layer in the power generation element including the plurality of unit cell layers is likely to be heated by the charge / discharge reaction, and the electrolyte is likely to be insufficient. Therefore, by disposing the electrolytic solution holding current collector in the central layer where the shortage of the electrolytic solution is likely to occur, the electrolytic solution can be quickly and efficiently supplied from the electrolytic solution holding part existing in the vicinity of the active material layer where the electrolytic solution is insufficient. Can be supplied. In particular, since the bipolar battery described later has a large number of single battery layers, an electrolyte shortage tends to occur in the central layer. For this reason, in a bipolar battery, the effect by this form can be exhibited notably.

  In addition, since the negative electrode has a larger volume expansion during charge / discharge than the positive electrode, the problem of insufficient electrolyte mainly occurs on the negative electrode side. For this reason, it is preferable that the negative electrode side current collector (negative electrode current collector) is formed to include an electrolyte solution holding portion. By installing the electrolytic solution holding part on the current collector on the negative electrode side where shortage of the electrolytic solution occurs, it is possible to prevent shortage of the electrolytic solution and more effectively suppress the increase in the resistance of the electrode.

  FIG. 4 is a schematic cross-sectional view (schematic cross-sectional view in a plane parallel to the stacking direction of the power generating elements) of the electrolyte non-holding current collector used in one embodiment of the present invention. As shown in FIG. 4, the electrolyte non-holding current collector has a configuration including, for example, a conductive layer 25.

  Hereinafter, members constituting the current collector will be described.

(Conductive layer)
The conductive layer has a current collecting function in the nonaqueous electrolyte battery of the present invention, and is composed of a conductive base material (conductive base material).

  The base material having conductivity is not particularly limited, and a material conventionally used as a current collector material for a battery can be appropriately employed. Specifically, at least one current collector selected from the group consisting of iron, stainless steel, chromium, nickel, manganese, titanium, molybdenum, vanadium, niobium, aluminum, copper, silver, gold, platinum, and carbon A conductive layer made of a material can be used. Among these, aluminum and copper are preferable from the viewpoints of electronic conductivity and battery operating potential.

  The nonaqueous electrolyte secondary battery of the present invention is characterized in that at least one of the current collectors included in the power generation element includes an electrolyte solution holding portion in addition to the conductive layer. Hereinafter, the electrolytic solution holding current collector shown in FIG. 2 will be described in detail as an example, but the technical scope of the present invention is not limited to such a form.

  In the electrolytic solution holding current collector, the electrolytic solution holding part supplies and supplies the electrolytic solution to and from the active material layer, and such supply and demand of the electrolytic solution is made through the conductive layer or through a space outside the conductive layer. The For this reason, at least one of the current collectors including the electrolytic solution holding part, that is, the conductive layer constituting the electrolytic solution holding current collector, has a hole through which the electrolytic solution can penetrate in the stacking direction of the electrolytic solution holding current collector. It is preferable to have (through hole). When it has such a form, electrolyte solution can be uniformly and rapidly supplied to the whole active material layer through a through-hole from an electrolyte solution holding | maintenance part. In particular, in order to improve the supply of the electrolytic solution to the negative electrode where the electrolyte shortage is likely to occur, a conductive layer (conductive layer constituting the negative electrode current collector) in contact with one side of the negative electrode active material layer is provided. It is preferable to have a through hole.

  The form of the through hole in the conductive layer is not particularly limited as long as the electrolytic solution can move between the electrolytic solution holding part and the active material layer, and can take any shape. The cross-sectional shape of the through hole is not particularly limited, and may be an indefinite shape in addition to a specific shape such as a circular shape, an elliptical shape, a triangular shape, a quadrangular shape, a star shape, a cross shape, or other polygonal shapes. . In addition, these shapes may be used alone, or a plurality of shapes may be used in combination.

  The average pore diameter of the through holes is preferably 10 nm or more from the viewpoint of smooth supply and demand of the electrolytic solution. The upper limit of the average hole diameter of the through holes is not particularly limited as long as the mechanical strength of the current collector is ensured, but is preferably 1 mm or less. In the present invention, the “average diameter of through-holes” refers to the average value of the diameters of the through-holes existing in the conductive layer. In the present invention, the absolute maximum length of the diameter of the through-holes is used as the diameter of the through-holes. . The method for measuring the average hole diameter of the through holes is not particularly limited. For example, a method of measuring the hole diameters of the through holes in the conductive layer observed by SEM and arithmetically averaging them can be used.

  From the viewpoint of uniform and rapid supply of the electrolytic solution, the conductive layer preferably has a plurality of through holes. However, when the volume occupied by the through holes in the conductive layer is large, the mechanical strength of the conductive layer may not be ensured. Therefore, the occupied volume of the through holes in the conductive layer is preferably 10% to 70%, more preferably 20% to 70%, and particularly preferably 30% to 70%.

  Further, the arrangement form of the plurality of through holes is not particularly limited, and may be a regular arrangement form or an irregular arrangement form. Further, different through holes may be combined in the conductive layer. However, from the viewpoint of supply and demand of a uniform electrolyte solution between the active material layer and the electrolyte solution holding part, it is preferable that the through holes are uniformly arranged in the conductive layer.

  The method for forming such a through hole is not particularly limited, and a conventionally known method can be used. For example, mechanical processing such as punching press processing, chemical processing such as etching, laser processing, or the like may be performed as appropriate in accordance with the form of the through hole to be provided.

  For reference, FIG. 5 shows a schematic cross-sectional view (schematic cross-sectional view in a plane perpendicular to the stacking direction of power generation elements) of a conductive layer having a through hole that can be used in an embodiment of the present invention. The schematic cross-sectional view of the conductive layer shown in FIG. 5 is a schematic cross-sectional view when the conductive layer 25 constituting the current collector of the embodiment shown in FIG. 2 is cut along a plane perpendicular to the stacking direction of the power generation elements. It corresponds to. In the conductive layer 25 shown in FIG. 5, a plurality of circular through holes 29 are regularly formed in the conductive substrate 28.

  Although there is no restriction | limiting in particular about the thickness of an electroconductive layer, Usually, they are about 1 micrometer-100 micrometers, Preferably they are 5 micrometers or more and 50 micrometers or less. If it is in such a range, the current collecting function can be exhibited without lowering the energy density.

(Electrolyte holding part)
The electrolytic solution holding unit is a layer that holds the electrolytic solution. The electrolytic solution holding part releases and absorbs the electrolytic solution when the electrode expands and contracts, and functions as a supply and demand layer for the electrolytic solution that is insufficient due to the expansion and contraction of the electrode.

  The form of the electrolytic solution holding part is not particularly limited as long as the electrolytic solution can be held, and may be various forms. For example, the electrolyte solution holding part of the present invention may have a form in which the electrolyte solution is held in the pores of the electrolyte holding substrate.

  The arrangement of the holes in the electrolyte solution holding part is not particularly limited as long as a sufficient amount of electrolyte solution can be held and smooth supply and demand of the electrolyte solution can be achieved. For example, the pores may be formed uniformly throughout the electrolyte holding part and the electrolyte may be dispersed and held, or the holes may be provided in a part of the electrolyte holding part to hold the electrolyte. May be.

  The porosity of the electrolytic solution holding part is preferably 20 to 70%, more preferably 30 to 70%, and further preferably 40 to 70%. When the porosity is in the above range, both the retained amount of the electrolytic solution and the mechanical strength of the electrolytic solution holding unit can be ensured.

In the present invention, the porosity of the electrolytic solution holding part means the ratio of the total volume of pores (pores) existing inside the electrolytic solution holding part to the volume of the electrolytic solution holding part. The method for measuring the porosity is not particularly limited. For example, the porosity can be calculated from the bulk density ρ of the electrolytic solution holding part of the final product and the true density ρ _{0 of the} raw material constituting the electrolytic solution holding part using the following formula. Here, “bulk density” refers to the density in consideration of the pores inside the electrolyte solution holding portion, and “true density” refers to the theoretical density that does not consider the pores of the raw material constituting the electrolyte solution holding portion. Further, the volume of pores (micropores) existing inside the electrolyte holding part can be measured by pore distribution measurement by a mercury intrusion method or the like, and can be obtained as a ratio to the volume of the electrolyte holding part.

  The shape of the hole is not particularly limited as long as the electrolytic solution can move between the electrolytic solution holding unit and the active material layer, and can take any shape. Further, the cross-sectional shape of the hole portion is not particularly limited, and may be an indefinite shape in addition to a specific shape such as a circular shape, an elliptical shape, a triangular shape, a quadrangular shape, a star shape, a cross shape, or other polygonal shapes. May be. These shapes may be used alone, or a plurality of shapes may be used in combination. In addition, it is preferable that the void | hole part of an electrolyte solution holding | maintenance part has at least 1 opening part so that absorption and discharge | release of electrolyte solution are attained.

  As the electrolytic solution holding part, one that can not only hold the electrolytic solution but also can smoothly supply the electrolytic solution into the electrode layer at the time of electrode reaction is suitable. For this reason, in a preferred embodiment, the pores are formed from one or more pores and may be in the form of pores. The pore diameter (pore diameter) of the electrolytic solution holding part is preferably 100 nm or more and 10 μm or less, more preferably 300 nm or more and 10 μm or less, and particularly preferably 500 nm or more and 10 μm or less. If the pore diameter is 10 μm or less, the pore diameter is smaller than the average particle diameter of the active material, so that clogging due to penetration of the active material into the electrolyte holding section can be prevented, and the mechanical strength of the electrolyte holding section can be increased. It can be secured. On the other hand, if the pore diameter is 100 nm or more, the diffusion of the electrolytic solution in the electrolytic solution holding part is good, and the electrolytic solution is smoothly absorbed and released, which is preferable.

  In the present invention, the “hole diameter” means an average value of the hole diameters of the hole portions existing in the electrolyte solution holding portion. In the present invention, the absolute maximum length of the holes is used as the hole diameter. The method for measuring the pore diameter is not particularly limited, but for example, it can be measured by pore distribution measurement by mercury porosimetry.

  Furthermore, from the viewpoint of more uniformly supplying the electrolytic solution to the active material layer, the electrolytic solution holding part is preferably composed of a porous body. In the present invention, the “porous body” means one having a large number of continuous or discontinuous pores. The shape and structure of the porous body are not particularly limited as long as it is porous, and may be various forms such as a three-dimensional network, honeycomb, and sponge.

  When the electrolytic solution holding part is a porous body, since the electrolytic solution holding part has a large number of pores (pores) inside the porous body, a sufficient amount of the electrolytic solution is uniformly held in the electrolytic solution holding part. And the electrolyte supply and demand capability can be improved.

  As a material which comprises such a porous body, if it has the above structures, it will not restrict | limit, A conventionally well-known thing can be used. For example, polyolefins such as polyethylene (PE) and polypropylene (PP), laminates having a three-layer structure of PP / PE / PP, microporous films such as polyimide and aramid; aramid, rayon, glass nonwoven fabric, polyester, Nonwoven fabrics such as polyimide, cotton, acetate, nylon, and ceramic can be used. Moreover, these may be used independently and may be used in combination.

  Moreover, it is preferable that an electrolyte solution holding | maintenance part is comprised from an elastic body. Since the electrolytic solution holding part which is an elastic body is rich in flexibility, it becomes possible to absorb the change in the cell thickness accompanying the expansion and contraction of the electrode. That is, the electrolytic solution holding part functions as a buffer layer that absorbs the change in cell thickness, and the volume change of the cell due to expansion and contraction can be suppressed.

  The elastic body is not particularly limited as long as it can function as a buffer layer when the electrode expands and contracts. However, the elastic modulus is preferably 10 cN / dtex or more and 150 cN / dtex, more preferably 10 cN / dtex or more and 120 cN / dtex or less, and particularly preferably 10 cN / dtex or more and 100 cN / dtex or less. An electrolyte solution holding part having an elastic modulus in the above range is preferable because sufficient strength and flexibility are secured to function as a buffer layer. The elastic modulus in the present invention means an initial tensile resistance specified in JIS L1013 and can be measured according to the specification.

  The material constituting such an elastic body is not particularly limited as long as it has the above-described configuration, and conventionally known materials can be used. Examples thereof include elastomer films such as polyolefin, polystyrene, polyester, polyamide, polyimide, polyurethane; and nonwoven fabrics such as aramid, rayon, glass nonwoven fabric, polyester, polyimide, cotton, acetate, and the like. Moreover, these may be used independently and may be used in combination.

  In the present invention, the electrolytic solution holding part is disposed in a current collector inside the power generation element. As described above, since the electrolytic solution holding part is installed other than between the electrodes, the distance between the positive electrode and the negative electrode is not increased, thereby preventing the output characteristics of the battery from being deteriorated. In addition, since the electrolytic solution holding part is disposed inside the power generation element, it does not require complicated electrolytic solution supply means that are often required when disposed outside the power generation element, and makes the electrolytic solution easy and effective. Supply and demand.

  When the electrode expands, an electrolyte for replenishing the insufficient electrolyte is supplied from the electrolyte holding part into the active material layer. On the other hand, when the electrode contracts, excess electrolyte in the active material layer is supplied to the electrolyte holding part. Absorbed. Thus, the electrolytic solution holding part of the present invention absorbs and discharges the electrolytic solution with the active material layer. When there is no electrolytic solution holding part, local shortage of the electrolytic solution is likely to occur in the negative electrode having large expansion and in the vicinity thereof. Even when an excessive amount of the electrolytic solution is present, there is no portion that absorbs the excessive amount of the electrolytic solution, so that the retention of the electrolytic solution becomes uneven through charge / discharge of the battery, and the active material has a large expansion and contraction. There may still be a shortage of electrolyte in the layer. In the present invention, an electrolyte that becomes excessive in the active material layer during contraction can be held in the nearby electrolyte holding part, while an insufficient electrolyte is supplied to the active material layer from the nearby electrolyte holding part during expansion. Therefore, the electrolytic solution can be held uniformly in the power generation element.

  The electrolytic solution holding part is preferably made of a material having a liquid absorption rate (absorption rate) of the electrolytic solution that is equal to or lower than the liquid absorption rate (absorption rate) of the active material layer (positive electrode active material layer and negative electrode active material layer). In the present invention, the “liquid absorption rate” means the ratio of the total mass of the electrolyte solution absorbed in the electrolyte solution holding part or active material layer to the mass of the electrolyte solution holding part or active material layer in a dry state, It can be calculated by the following formula.

  The liquid absorption rate can be measured, for example, by a method based on JIS R2205.

  If the liquid absorption rate of the electrolytic solution in the electrolytic solution holding part is less than the value of the liquid absorption rate of the electrolytic solution in the active material layer, transfer (absorption) of the electrolytic solution from the active material layer to the electrolytic solution holding part is more than necessary Can be suppressed. Therefore, the required amount of electrolyte is smoothly supplied to the active material layer lacking the electrolyte, and when the active material layer becomes excessive, only the excess amount of electrolyte is held in the electrolyte holder. be able to. However, since an electrolytic solution can be supplied to the active material layer as long as a sufficient amount of the electrolytic solution is ensured, the electrolyte may be made of a material having a larger liquid absorption rate than the active material layer.

  The electrolytic solution holding part may or may not have conductivity. Since the current collector is in contact with the tab portion via the conductive layer, the electrolyte solution holding portion does not necessarily have conductivity.

  The thickness of the electrolytic solution holding part is not particularly limited, but is preferably 5 μm or more and 500 μm or less, more preferably 5 μm or more and 300 μm or less, and particularly preferably 5 μm or more and 100 μm or less. When the thickness is 5 μm or more, it is possible to absorb the change in the electrode thickness during the expansion and contraction of the electrode and to secure the amount of electrolyte retained. On the other hand, if it is 500 micrometers or less, the capacity | capacitance of the battery per volume can be enlarged, and the improvement of an energy density will be aimed at.

  As described above, the electrolyte solution holding unit used in the present invention can function as an electrolyte supply / demand layer and a buffer layer for cell thickness change in the nonaqueous electrolyte secondary battery. In addition, the electrolyte solution holding | maintenance part of this invention may be the single layer form comprised with the single material, and the multilayer form which laminated | stacked the layer comprised with the several material may be sufficient as it.

(Electrolyte)
The electrolytic solution to be held in the electrolytic solution holding part is not particularly limited as long as it has a function as a lithium ion carrier that moves between the positive and negative electrodes during charge and discharge and can be impregnated into the base material of the electrolytic solution holding part. Alternatively, an electrolyte excluding a solid form can be used. Specifically, a liquid electrolyte or a gel polymer electrolyte can be used.

The liquid electrolyte has a form in which a lithium salt as a supporting salt is dissolved in an organic solvent as a plasticizer. Examples of the organic solvent that can be used as the plasticizer include carbonates such as ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), and diethyl carbonate (DEC). As the supporting salt (lithium _{salt), LiPF 6, LiBF 4,} LiClO 4, LiAsF 6, LiTaF 6, LiAlCl 4, Li 2 B 10 Cl ₁₀ and the like inorganic acid anionic _salt; LiCF ₃ SO _3, Li ( Compounds that can be added to the active material layer of the electrode, such as organic acid anion salts such as CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, can be similarly employed.

  The gel polymer electrolyte is a kind of polymer electrolyte, and has a configuration in which the liquid electrolyte is injected into a matrix polymer (host polymer) made of an ion conductive polymer. The ion conductive polymer used as the matrix polymer (host polymer) is not particularly limited. For example, polyethylene oxide (PEO), polypropylene oxide (PPO), polyvinylidene fluoride (PVDF), a copolymer of polyvinylidene fluoride and hexafluoropropylene (PVDF-HFP), polyethylene glycol (PEG), polyacrylonitrile (PAN), Examples thereof include polymethyl methacrylate (PMMA) and copolymers thereof. Here, the ion conductive polymer may be the same as or different from the ion conductive polymer used as the electrolyte in the positive electrode active material layer and the negative electrode active material layer, but is preferably the same. . The type of the electrolytic solution (electrolyte salt and plasticizer) is not particularly limited, and an electrolyte salt such as the lithium salt exemplified above and a plasticizer such as carbonates may be used.

  The matrix polymer of the gel polymer electrolyte can exhibit excellent mechanical strength by forming a crosslinked structure. In order to form a cross-linked structure, polymerization such as thermal polymerization, ultraviolet polymerization, radiation polymerization, and electron beam polymerization is performed on a polymerizable polymer (for example, PEO or PPO) for forming a polymer electrolyte, using an appropriate polymerization initiator. What is necessary is just to process.

  In addition, the electrolyte contained in the electrolytic solution holding unit may be one type alone or two or more types. In addition, an electrolyte different from the electrolyte used for the electrolyte layer and / or the active material layer described later may be used, but it is preferable to use the same electrolyte as the electrolyte used for the electrolyte and / or the active material layer.

  There is no restriction | limiting in particular also about the holding | maintenance amount of the electrolyte solution in an electrolyte solution holding layer. However, when the battery is discharged (electrode contraction), the electrolyte retention rate of the electrolyte retention layer (the proportion of the electrolyte retained in the electrolyte retention portion) is the electrolyte retention rate of the electrode (the void in the electrode layer). The ratio is preferably smaller than the ratio of the electrolytic solution being retained. On the other hand, when the battery is charged (electrode expansion), the electrolyte retention rate of the electrolyte retention layer is preferably greater than the electrolyte retention rate of the electrode. In the case of such a configuration, when the electrolyte in the active material layer is insufficient, a sufficient amount of electrolyte can be supplied to the active material layer. In addition, when the amount of the electrolyte in the active material layer becomes excessive, an excessive amount of the electrolyte can be accommodated in the electrolyte holding layer, so that the electrolyte can be uniformly and smoothly absorbed and supplied.

  When using an integrated electrolyte holding current collector, a hole for holding the electrolyte is provided inside the conductive layer, and the electrolyte is held in the hole to form an electrolyte holding layer. Also good. Alternatively, an electrolyte solution holding substrate may be installed inside the conductive layer, and the electrolyte solution may be held in the pores of the electrolyte solution holding substrate to form an electrolyte solution holding layer. As the shape and material of the electrolyte solution holding layer provided inside the conductive layer, the same ones as described above can be suitably used.

  Note that the thickness of the integrated electrolytic solution holding current collector is preferably 5 μm or more and 700 μm or less, more preferably 5 μm or more and 500 μm or less, and particularly preferably 10 μm or more and 100 μm or less.

  Since the nonaqueous electrolyte secondary battery of the present invention has such an electrolyte solution holding layer, it prevents the lack of electrolyte solution due to the expansion and contraction of the electrode during charge and discharge without deteriorating the output characteristics of the battery. An increase in resistance can be suppressed. Therefore, a nonaqueous electrolyte secondary battery having excellent charge / discharge cycle characteristics can be obtained.

[Negative electrode active material layer]
The negative electrode active material layer contains a negative electrode active material, and a conductive agent, binder, electrolyte (polymer matrix, ion conductive polymer, electrolytic solution, etc.) for increasing electrical conductivity and an electrolyte for increasing ion conductivity as required. It further comprises a supporting salt (lithium salt) and the like.

  The compounding ratio of the components contained in the negative electrode active material layer is not particularly limited, and can be adjusted by appropriately referring to known knowledge about the nonaqueous electrolyte secondary battery. Moreover, there is no restriction | limiting in particular also about the thickness of an active material layer, The conventionally well-known knowledge about a nonaqueous electrolyte secondary battery can be referred suitably. For example, the thickness of the active material layer is about 2 to 100 μm.

(Negative electrode active material)
The negative electrode active material used in the nonaqueous electrolyte secondary battery of the present invention is not particularly limited as long as it can reversibly occlude and release lithium, but preferably contains an element that forms an alloy with lithium. By using an element that forms an alloy with lithium, it is possible to obtain a high-capacity battery having a higher energy density than conventional carbon-based materials. In addition, a material containing an element that is alloyed with lithium causes a large volume expansion during charging, and accordingly, a large amount of electrolyte is consumed. The present invention is characterized in that the electrolytic solution is supplied by the electrolytic solution holding part during discharge and the insufficient electrolytic solution is replenished, and the effect of the present invention is most exhibited when an active material having a large volume change is used. The Examples of the form containing an element that forms an alloy with lithium include a single element that forms an alloy with lithium, an oxide containing these elements, and the like.

  The element alloying with lithium is not limited to the following, but specifically, Si, Ge, Sn, Pb, Al, In, Zn, H, Ca, Sr, Ba, Ru, Rh, Ir, Pd, Pt, Ag, Au, Cd, Hg, Ga, Tl, C, N, Sb, Bi, O, S, Se, Te, Cl, and the like. Among these, it is preferable that at least one element selected from the group consisting of Si, Ge, Sn, Pb, Al, In, and Zn is included from the viewpoint that a battery having excellent capacity and energy density can be configured. More preferably, Si, or Sn is contained, and Si is particularly preferred. These may be used alone or in combination of two or more.

In addition, carbon materials such as graphite, soft carbon, and hard carbon, metal materials, lithium-transition metal composite oxides such as lithium-titanium composite oxide (lithium titanate: Li ₄ Ti ₅ O ₁₂ ), and other conventional materials A known negative electrode active material can be used. In some cases, two or more negative electrode active materials may be used in combination.

(Conductive agent)
The conductive agent refers to an additive blended to improve conductivity. The electrically conductive agent used for the nonaqueous electrolyte secondary battery of the present invention is not particularly limited, and conventionally known ones can be used. Examples thereof include carbon materials such as carbon black such as acetylene black, graphite, and carbon fiber. When the conductive agent is included, an electronic network inside the active material layer is effectively formed, which can contribute to improvement of the output characteristics of the battery.

(binder)
The negative electrode active material layer may contain a binder. The binder plays a role of maintaining the electrode structure by binding the active materials or the active material and the current collector. Examples of the binder include, but are not limited to, thermoplastic resins such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl acetate, polyimide, and acrylic resins, epoxy resins, polyurethane resins, And thermosetting resins such as urea resins, and rubber-based materials such as styrene butadiene rubber (SBR).

(Electrolyte / Supporting salt)
Examples of the electrolyte include, but are not limited to, ion conductive polymers (solid polymer electrolytes) including lithium salts such as polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof. There is nothing.

The supporting salt (lithium salt), but are not limited _{to, LiPF 6, LiBF 4, LiClO} 4, LiAsF 6, LiTaF 6, LiAlCl 4, inorganic acid anion salts such as _{Li 2 B 10 Cl 10; LiCF} 3 SO ₃ , organic acid anion salts such as Li (CF ₃ SO ₂ ) ₂ N and Li (C ₂ F ₅ SO ₂ ) ₂ N. These supporting salts may be used alone or in combination of two or more.

[Positive electrode active material layer]
The positive electrode active material layer includes a positive electrode active material, and further includes a conductive agent, a binder, an electrolyte, an electrolyte supporting salt, and the like as necessary. Since the components other than the positive electrode active material among the components of the positive electrode active material layer are the same as those described above, the description thereof is omitted here. The compounding ratio of the components contained in the positive electrode active material layer and the thickness of the positive electrode active material layer are not particularly limited, and conventionally known knowledge about the nonaqueous electrolyte secondary battery can be referred to as appropriate.

(Positive electrode active material)
The positive electrode active material used in the non-aqueous electrolyte secondary battery of the present invention is not particularly limited as long as it is a material capable of occluding and releasing lithium, and a positive electrode active material usually used in lithium ion secondary batteries can be used. . Specifically, a lithium-transition metal composite oxide is preferable. For example, a Li—Mn composite oxide such as LiMn ₂ O _4, a Li—Ni composite oxide such as LiNiO ₂ , LiNi _0.5 Mn _0. A Li—Ni—Mn based composite oxide such as ₅ O ₂ can be given. In some cases, two or more positive electrode active materials may be used in combination.

[Electrolyte layer]
The electrolyte layer is a layer containing a non-aqueous electrolyte. A nonaqueous electrolyte (specifically, a lithium salt) contained in the electrolyte layer has a function as a carrier of lithium ions that moves between the positive and negative electrodes during charge and discharge. Although it will not specifically limit if such a function can be exhibited as a non-aqueous electrolyte, In addition to the liquid electrolyte illustrated in the electrolyte solution holding | maintenance part and the gel polymer electrolyte, an intrinsic polymer electrolyte can be used. About the specific form of a liquid electrolyte and a gel polymer electrolyte, since the thing similar to the form demonstrated by the electrolyte solution holding | maintenance part can be used, the detail is abbreviate | omitted here.

  The intrinsic polymer electrolyte is a kind of polymer electrolyte and has a form that does not contain an electrolytic solution. Specifically, the intrinsic polymer electrolyte has a structure in which a supporting salt (lithium salt) is dissolved in a matrix polymer (host polymer) made of an ion conductive polymer, and does not include an organic solvent that is a plasticizer. Therefore, by using an intrinsic polymer electrolyte as the electrolyte, there is no fear of liquid leakage from the battery, and the battery reliability can be improved.

  As the matrix polymer (host polymer) and the supporting salt (lithium salt), those exemplified in the electrolytic solution holding part can be used similarly. Further, the matrix polymer of the intrinsic polymer electrolyte may form a cross-linked structure by an appropriate polymerization treatment, similarly to the gel polymer electrolyte. The nonaqueous electrolyte contained in the electrolytic solution holding part may be one kind alone, or two or more kinds.

  In addition, when an electrolyte layer is comprised from a liquid electrolyte or a gel polymer electrolyte, you may use a separator for an electrolyte layer. Specific examples of the separator include a microporous film made of polyolefin such as polyethylene or polypropylene.

  It can be said that the thinner the electrolyte layer, the better to reduce the internal resistance. The thickness of the electrolyte layer is 1 to 100 μm, preferably 5 to 50 μm.

[tab]
In the laminated battery 10, the conductive layers in the respective negative electrode current collectors 11 (including 11 a) and the positive electrode current collector 14 are collected at the end of the power generation element 17 for the purpose of taking out current to the outside of the battery. It is electrically connected to (positive electrode tab 19 and negative electrode tab 18). Further, these tabs (18, 19) are taken out of the laminate sheet 22 which is an exterior. Specifically, a laminate in which a negative electrode tab 19 electrically connected to each of the negative electrode current collectors 11 and 11 a and a positive electrode tab 18 electrically connected to each of the positive electrode current collectors 14 are exteriors. The sheet 22 is taken out.

  The material which comprises a tab (the positive electrode tab 19 and the negative electrode tab 18) is not restrict | limited in particular, The well-known material conventionally used as a tab for laminated batteries can be used. Examples of the constituent material of the tab include aluminum, copper, titanium, nickel, stainless steel (SUS), and alloys thereof. The positive electrode tab 19 and the negative electrode tab 18 may be made of the same material or different materials. As a connection method, a separately prepared tab (18, 19) may be connected to the current collector (11, 14) as in this embodiment, or the current collector may be extended to form a tab. . Further, the current collector (11, 14) and the tab (18, 19) may be electrically connected via the positive terminal lead 21 and the negative terminal lead 20.

[Exterior]
In a non-aqueous electrolyte secondary battery, it is desirable to accommodate the entire power generating element in a battery exterior material or battery case in order to prevent external impact and environmental degradation during use. As the exterior material, a conventionally known metal can case can be used, and a bag-like case that can cover a power generation element using a laminate sheet containing aluminum can be used.

  Since the metal can case type exterior body has strength, it can absorb even if the power generation element in the can expands and contracts somewhat, and the thickness of the cell does not change. Moreover, it is possible to obtain a can case having a desired strength and size by examining the material of the can, the design of the plate thickness, the clearance between the outer can and the power generation element, and the like.

  The polymer-metal composite laminate sheet is not particularly limited, and a conventionally known sheet formed by arranging a metal film between polymer films and laminating and integrating the whole can be used. Specifically, it is arranged as an outer protective layer (laminated outermost layer) made of a polymer film, a metal film layer, a heat-sealing layer (laminated innermost layer) made of a polymer film, and the whole is laminated and integrated. Is mentioned.

  Among these, it is particularly preferable to use an aluminum laminate film outer package having a high degree of freedom in shape. In the present invention, “aluminum laminate” refers to a laminate containing aluminum.

  Specific examples of the aluminum laminate film include, but are not limited to, a three-layer laminate film in which polypropylene (PP), aluminum, and nylon are laminated in this order.

[Bipolar battery]
The battery of the present invention may be a bipolar non-aqueous electrolyte secondary battery (hereinafter also referred to as “bipolar battery”).

  The bipolar battery includes a positive electrode having a positive electrode active material layer electrically coupled to one surface of a current collector, and a negative electrode having a negative electrode active material layer electrically coupled to the other surface of the current collector. And a non-aqueous electrolyte secondary battery in which an electrolyte layer disposed between a positive electrode and a negative electrode is alternately laminated.

  Bipolar batteries are preferred because they have the advantage of having a higher power density and higher voltage than stacked batteries. A stacked battery takes lead wires from each of a positive electrode and a negative electrode, and is connected to an adjacent battery via the lead wires. For this reason, the conduction path of electrons becomes longer corresponding to the length of the lead wire, and the output of the battery is lowered. On the other hand, in the bipolar battery, current flows in the vertical direction (electrode stacking direction) through the current collector, so that the electron conduction path can be shortened and the output is high.

  FIG. 6 is a schematic cross-sectional view showing a bipolar nonaqueous electrolyte secondary battery according to another embodiment of the present invention. The bipolar battery 30 of this embodiment shown in FIG. 6 has a structure in which a substantially rectangular power generation element 37 in which a charge / discharge reaction actually proceeds is sealed inside a laminate sheet 42 that is an exterior.

  As shown in FIG. 6, the power generation element 37 of the bipolar battery 30 of this embodiment includes a plurality of bipolar electrodes 34. The bipolar electrode 34 has a structure including a positive electrode in which a positive electrode active material layer 35 is provided on one surface of a current collector 31 and a negative electrode in which a negative electrode active material layer 32 is provided on the other surface. That is, the bipolar battery 30 includes a bipolar electrode having a positive electrode having a positive electrode active material layer 35 formed on one surface of a current collector 31 and a negative electrode having a negative electrode active material layer 32 formed on the other surface. 34 is provided with a power generation element 37 having a single cell layer 36 formed by laminating 34 through an electrolyte layer 33. In the form shown in FIG. 6, the electrolyte layer 33 holds a non-aqueous electrolyte.

  The current collector 31 includes a conductive layer, and at least one of the current collectors 31 included in the power generation element 37 has a configuration including an electrolyte solution holding portion in addition to the conductive layer. In the case of a bipolar battery, the current collector (electrolyte holding current collector) including the electrolytic solution holding part has no through hole from the positive electrode active material layer to the negative electrode active material layer, and one surface of the conductive layer It is necessary to have a configuration in which the opening of the electrolytic solution holding part exists only. If a through hole from the positive electrode active material layer to the negative electrode active material layer exists in the electrolyte holding current collector, an electrode reaction occurs in the current collector, so that it cannot function as a bipolar battery.

  In addition, an insulating layer (seal part) 43 is disposed around the single cell layer 36 in order to prevent liquid junction due to leakage of the electrolyte from the single cell layer 36. By providing the insulating layer (seal part) 43, it is possible to insulate between the adjacent current collectors 31 and prevent a short circuit due to contact between the adjacent electrodes (the positive electrode active material layer 35 and the negative electrode active material layer 32). .

  Further, the conductive layer in the outermost layer current collector 31b on the positive electrode side is electrically connected to the positive electrode tab 39 electrically connected, and the conductive layer in the outermost layer current collector 31a on the negative electrode side is electrically connected. Connected to the negative electrode tab 38. And the electric power generation element 37 is sealed in the exterior material which consists of the laminate sheet 42 so that these positive electrode tabs 39 and the negative electrode tabs 38 may lead out outside. The outermost layer current collector (31a, 31b) and the tab (38, 39) may be electrically connected via the positive terminal lead 41 and the negative terminal lead 40.

  Hereinafter, although the member which comprises the bipolar battery 30 of this embodiment is demonstrated easily, since the electrode component, a tab, and an exterior are the same as the content described above among the components of the said bipolar battery. The description is omitted here.

[Insulation layer]
In the bipolar battery 30, an insulating layer (seal part) 43 is usually provided around each single battery layer 36. This insulating layer (seal part) 43 prevents the adjacent current collectors 31 in the battery from coming into contact with each other and short-circuiting due to slight irregularities at the end of the unit cell layer 36 in the power generation element 37. It is provided for the purpose. By providing such an insulating layer 43, long-term reliability and safety are ensured, and a high-quality bipolar battery 30 can be provided.

  As described above, since the bipolar battery has a cell structure in which an electrode provided with an insulating layer (seal part) is stacked around a single battery layer, a change in cell thickness, that is, a follow-up of a current collector in the cell. May cause breakage of the insulating layer (seal portion), and may reduce the reliability of the battery. In the bipolar battery of the present invention, the electrolytic solution holding part can function as a buffer layer that absorbs changes in cell thickness. For this reason, even when a lithium alloy negative electrode material is used, the cell thickness hardly changes, and a highly reliable bipolar battery can be provided.

  Any insulating layer may be used as long as it has insulating properties, sealing properties against falling off of the solid electrolyte, sealing properties against moisture permeation from the outside (sealing properties), heat resistance at the battery operating temperature, and the like. For example, urethane resin, epoxy resin, polyethylene resin, polypropylene resin, polyimide resin, or rubber can be used. Of these, urethane resins or epoxy resins are preferred from the viewpoints of corrosion resistance, chemical resistance, ease of production (film forming properties), economy, and the like.

[Battery manufacturing method]
The manufacturing method of the stacked battery and bipolar battery of the present embodiment is not particularly limited, and can be manufactured by applying a conventionally known method. Hereinafter, although the manufacturing method of the nonaqueous electrolyte secondary battery of this invention is demonstrated, the technical scope of this invention should be defined based on description of a claim, and is not restrict | limited only to the following forms.

  According to another aspect of the present invention, a negative electrode in which a negative electrode active material layer containing a negative electrode active material is formed on the surface of a current collector containing a conductive layer, an electrolyte layer containing a nonaqueous electrolyte, and a positive electrode active material A method for producing a non-aqueous electrolyte secondary battery including a power generation element having a single battery layer in which a positive electrode active material layer containing a substance is formed on the surface of a current collector containing a conductive layer Is provided. In the non-aqueous electrolyte secondary battery, at least one of the current collectors included in the power generation element is an electrolyte solution holding current collector further including an electrolyte solution holding unit that holds the electrolyte solution. To do.

  The manufacturing method according to an embodiment of the present invention includes a step of producing a power generation element including at least one current collector including a conductive layer and an electrolyte solution holding unit (a step of producing a power generation element), A step of arranging the power generation element (a step of arranging the power generation element), and a step of impregnating the electrolytic solution holding part with the electrolytic solution under vacuum (an impregnation step of the electrolytic solution). By using such a method, the nonaqueous electrolyte secondary battery of the present invention having excellent capacity characteristics and output characteristics can be easily obtained. Hereinafter, the case of a stacked battery will be described as an example.

[Stacked battery]
1. First, a positive electrode active material slurry and a negative electrode active material slurry are prepared by dispersing a mixture of electrode slurries containing electrode materials such as an active material, a conductive agent and a binder in a slurry viscosity adjusting solvent.

  The slurry viscosity adjusting solvent is not particularly limited, and examples thereof include N-methyl-2-pyrrolidone (NMP). The slurry is converted into ink from the solvent and the solid content using a homogenizer or a kneader.

  Next, the slurry is applied to one side or both sides of the conductive layer. Note that a current collector (electrolyte non-retained current collector) that does not have an electrolytic solution holding portion is produced from the conductive layer in which the slurry is applied to both surfaces of the conductive layer. On the other hand, an electrolytic solution holding part is formed later on the opposite side of the conductive layer where the slurry is applied only on one side of the conductive layer, and a multilayer current collector in which the electrolytic solution holding part and the conductive layer are laminated. A body (electrolyte holding current collector) is produced. The application means for applying the slurry to the conductive layer is not particularly limited, and generally used means such as a self-propelled coater, a doctor blade method, and a spray method can be employed.

  Subsequently, the coating film formed on the surface of the conductive layer is dried. Thereby, the solvent in a coating film is removed. The drying means for drying the coating film is not particularly limited, and conventionally known knowledge about electrode production can be appropriately referred to. For example, heat treatment is exemplified. Drying conditions (drying time, drying temperature, etc.) can be appropriately set according to the amount of slurry applied and the volatilization rate of the slurry viscosity adjusting solvent. The resulting dried product is pressed to adjust the density, porosity, and thickness of the electrode, and a positive or negative electrode having an active material layer formed on one side of the conductive layer, or an active material layer on both sides of the conductive layer A positive electrode or negative electrode (electrolyte non-retained positive electrode or negative electrode) formed with is obtained.

  Next, an electrolyte solution holding substrate of the electrolyte solution holding unit is prepared, and two positive electrodes each having an active material layer formed on only one surface of the conductive layer and the electrolyte solution holding substrate are connected to the two positive electrodes. Are stacked so as to face each other. Similarly, two negative electrode layers in which an active material layer is formed only on one side of the conductive layer and an electrolyte solution holding substrate are stacked so that the two negative electrodes face each other with the electrolyte solution holding part therebetween. Thus, a positive electrode or a negative electrode (electrolyte holding positive electrode or negative electrode) in which an active material layer is formed on the surface of a current collector (multilayer electrolyte holding current collector) formed by sandwiching an electrolyte solution holding portion between two conductive layers ) Is obtained.

  When an integrated electrolyte holding current collector is used, an electrolytic solution holding part (or an electrolyte holding base material or a hole part that becomes an electrolyte holding part by impregnating the electrolytic solution later in the conductive layer) ) Is prepared in advance. The positive electrode having an active material layer formed on the surface of the integrated electrolyte holding current collector by applying the slurry on both sides of the integrated electrolytic solution holding current collector and drying it, followed by pressing. A negative electrode (electrolyte holding positive electrode or negative electrode) is obtained.

  The production method of the integrated electrolyte solution holding current collector is not particularly limited, and conventionally known methods can be referred to. For example, by performing chemical treatment such as etching, a hole portion may be provided on the surface of the conductive base material to form an electrolyte solution holding portion. The depth and the like of the pores can be controlled by adjusting the etching time, that is, the time of exposure to an etching agent such as an acid. Etching agents, etching conditions, and the like are not particularly limited, and conventionally known ones may be used in accordance with the conductive base material.

  Thereafter, the electrolyte holding positive electrode or negative electrode prepared above and, if necessary, the electrolyte non-holding positive electrode or negative electrode are laminated so that the positive electrode and the negative electrode face each other via a separator (corresponding to an electrolyte layer). Can be produced.

2. Next, the conductive layer contained in each positive electrode and negative electrode in the power generation element obtained above is bundled to weld the lead, and this is placed inside an exterior body such as an aluminum laminate film bag. Arrange.

3. Electrolyte impregnation step Thereafter, the electrolyte is injected into the exterior body by a liquid injector, the electrolyte holding part and the electrolyte layer are impregnated under vacuum, and the end is sealed under vacuum to obtain a battery. The degree of vacuum in this case is not particularly limited, but is preferably 1.0 kPa to 70 kPa. Such a vacuum is preferable because the impregnation of the electrolyte is good.

  When a gel polymer electrolyte is used, a gel polymer electrolyte precursor solution containing a matrix polymer, a liquid electrolyte, and a polymerization initiator is prepared, and the gel polymer electrolyte precursor solution is used as an electrolyte solution holding substrate or an electrolyte solution holding part. Apply to holes. Then, after impregnating the electrolytic solution holding part under vacuum, a crosslinking polymerization reaction is performed by heating or irradiation with ultraviolet rays or the like, and drying is performed, thereby obtaining an electrolytic solution holding part holding the gel polymer electrolyte.

  In addition, by applying the gel polymer electrolyte precursor solution to the upper surface of the active material layer formed on the conductive layer or the separator in the same manner as described above, impregnating under vacuum, cross-linking polymerization reaction, and drying An electrolyte layer containing a gel polymer electrolyte can be produced.

  And a power generation element is produced using the electrolyte holding part and electrolyte layer which have gel electrolyte, and after arranging in an exterior body, an edge part can be sealed under vacuum and it can be set as a battery.

  In the above, a laminated battery using a liquid electrolyte or a gel polymer electrolyte has been described as an example, but in the case where a genuine polymer electrolyte is used for other electrolyte layers or for the production of a bipolar battery using the above electrolyte, It can be implemented with reference to a known technique, and the description thereof is omitted here.

[Battery]
A plurality of the batteries of the present invention may be connected in parallel and / or in series to form an assembled battery. In the battery of the present invention, even when the negative electrode expands and contracts, the electrolytic solution holding part functions as an electrolytic solution supply and demand layer. Furthermore, when the electrolytic solution holding part is an elastic body, since the electrolytic solution holding part plays a role as a buffer layer, increase or decrease in thickness as a cell can be suppressed. For this reason, even when a lithium alloy-based negative electrode material is used, an assembled battery can be easily formed as in the conventional battery.

  FIG. 7 is a perspective view showing the assembled battery of the present embodiment.

  As shown in FIG. 7, the assembled battery 50 is configured by connecting a plurality of the stacked batteries 10 described in the above embodiment. Each stacked battery 10 is connected by connecting the positive electrode tab 19 and the negative electrode tab 18 of each stacked battery 10 using a bus bar. On one side surface of the assembled battery 50, electrode terminals (51, 52) are provided as electrodes of the entire assembled battery 50.

  A connection method for connecting the plurality of stacked batteries 10 constituting the assembled battery 50 is not particularly limited, and a conventionally known method can be appropriately employed. For example, a technique using welding such as ultrasonic welding or spot welding, or a technique of fixing using rivets, caulking, or the like can be employed. According to such a connection method, the long-term reliability of the assembled battery 50 can be improved.

  According to the assembled battery 50 of the present invention, since the individual stacked batteries 10 constituting the assembled battery 50 are excellent in charge / discharge cycle characteristics, an assembled battery excellent in charge / discharge cycle characteristics can be provided.

  In addition, the connection of the stacked batteries 10 constituting the assembled battery 50 may be all connected in parallel, or may be connected in series, and a combination of series connection and parallel connection is also possible. May be. As a result, the capacity and voltage can be freely adjusted.

[Battery module]
In the present invention, a plurality of assembled batteries may be connected to form an assembled battery module.

  FIG. 8 is a perspective view showing an assembled battery module in which a plurality of assembled batteries according to an embodiment of the present invention are connected. The assembled battery module 60 shown in FIG. 8 is a module in which a plurality of the assembled batteries 50 described above are stacked and the electrode terminals 51 and 52 of each assembled battery 50 are connected by conductive bars 61 and 62.

  As described above, by modularizing the assembled battery 50, battery control is facilitated, and for example, an assembled battery module that is optimal for mounting on an electric vehicle or a hybrid vehicle is obtained. Since the assembled battery module 60 uses the above-described assembled battery, it has high long-term reliability. Such an assembled battery module is also a kind of assembled battery.

  Such an assembled battery module is preferably used as a power source for a motor such as an electric vehicle. An automobile using the assembled battery module as a power source for a motor is an automobile whose wheels are driven by a motor, such as an electric vehicle and a hybrid vehicle.

[vehicle]
The battery of the present invention can be mounted on a vehicle using the above-described stacked battery 10, bipolar battery 30, assembled battery 50, or assembled battery module 60 as a motor driving power source. Examples of the vehicle using the stacked battery 10, the bipolar battery 30, the assembled battery 50, or the assembled battery module 60 as a motor power source include an automobile whose wheels are driven by a motor, and other vehicles (for example, a train). Examples of the automobile include a complete electric car that does not use gasoline, a hybrid automobile such as a series hybrid automobile and a parallel hybrid automobile, and a fuel cell automobile. As a result, it is possible to manufacture a vehicle having a longer life and higher reliability than conventional ones.

  For reference, FIG. 9 shows a schematic diagram of an automobile equipped with an assembled battery. The assembled battery 50 mounted on the automobile 70 has the characteristics as described above. For this reason, the automobile 70 equipped with the assembled battery 50 is a vehicle having excellent charge / discharge cycle characteristics.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications, omissions, and additions can be made by those skilled in the art.

  Hereinafter, the present invention will be described with reference to the accompanying drawings (FIGS. 10 to 13), but the technical scope of the present invention is not limited to these examples. 10 to 13 are schematic cross-sectional views showing the stacked battery or bipolar battery produced in Examples 1 to 4, respectively.

(Stacked battery)
[Example 1]
(1) Production of positive electrode element Lithium manganate (average particle size: 10 μm) (90 parts by mass) as a positive electrode active material, carbon black (6 parts by mass) as a conductive agent, and polyvinylidene fluoride (PVDF) as a binder # 1300) (4 parts by mass) was mixed to prepare a positive electrode mixture. This positive electrode mixture was dispersed in an appropriate amount of N-methyl-2-pyrrolidone as a slurry viscosity adjusting solvent to prepare a positive electrode active material slurry.

  As the conductive layer, an aluminum (Al) foil having a thickness of 20 μm was prepared. The slurry prepared above was applied to one side of the conductive layer, dried and pressed to produce a positive electrode element in which the positive electrode active material layer 15 having a thickness of 70 μm was formed on one side of the conductive layer 25. .

(2) Production of negative electrode element A negative electrode active material, a conductive agent, and a precursor solution of a binder were mixed to obtain a negative electrode mixture. In addition, silicon-based active material powder (average particle diameter: 10 μm) (80 parts by mass) was used as the negative electrode active material, and carbon black (10 parts by mass) was used as the conductive agent. As a binder precursor solution, an N-methyl-2-pyrrolidone solution (corresponding to 10 parts by mass as polyimide) containing a polyimide precursor (polyamic acid) serving as a binder was used. This negative electrode mixture was dispersed in an appropriate amount of an N-methyl-2-pyrrolidone solution, which is a slurry viscosity adjusting solvent, to prepare a negative electrode active material slurry.

  As a conductive layer, a copper (Cu) foil having a thickness of 20 μm was prepared, and the slurry prepared above was applied to one side of the conductive layer, dried and pressed, and then vacuum dried at 250 ° C. A negative electrode element in which the negative electrode active material layer 12 having a thickness of 30 μm was formed on one surface of the layer 25 was produced.

(3) Preparation of electrolyte solution holding part and electrolyte layer A polyolefin film (material: made of polyethylene (PE), thickness: 10 μm, porosity: 35%) was prepared as an electrolyte solution holding substrate used for the electrolyte solution holding part. .

  Moreover, also about the base material of the separator used for the electrolyte layer, the same base material as the electrolytic solution holding base material used for the electrolytic solution holding part was used.

(4) Production of power generation element The positive electrode element and the negative electrode element produced above were cut out leaving a tab part to be welded to an aluminum terminal or a nickel terminal so that the electrode part size was 100 mm × 100 mm. The separator and the electrolyte holding substrate of the electrolyte holding unit were also cut out to a size of 110 mm × 110 mm.

  The six positive electrode elements, the six negative electrode elements, the six separators, and the five electrolyte holding base materials prepared in this way were laminated using a jig to produce the power generation element shown in FIG. At that time, the positive electrode active material layer 15 and the negative electrode active material layer 12 face each other with a separator (electrolyte layer) 13 interposed therebetween, and the conductive layers 25 in the positive electrode element or the conductive layers 25 in the negative electrode element are in the electrolyte solution. It was made to oppose through the holding base material (electrolyte holding part) 26.

(5) Arrangement of power generation element, impregnation with electrolyte solution Terminal leads (20, 21) were welded to each of the conductive layers 25 in the power generation element produced above. In addition, the aluminum terminal lead 20 was welded about the electroconductive layer in a positive electrode element, and the nickel terminal lead 21 was welded about the electroconductive layer in a negative electrode element. Next, the power generation element is put inside an aluminum laminate film exterior 22 molded to the size of the power generation element, leaving one side for injecting the electrolyte, and heat-sealing the remaining three sides to form a bag. . A predetermined amount of electrolyte was injected and impregnated in the interior under vacuum (degree of vacuum: 50 [kPa]), and then the remaining one side was vacuum-sealed to produce a stacked battery.

As the electrolyte, LiPF ₆ is a lithium salt in a mixed solvent of ethylene carbonate (EC) (30 parts by volume) and dimethyl carbonate (DMC) (70 parts by volume) is dissolved in a concentration of 1 mol · ^{dm -3} The solution was used. The amount of the electrolyte used is an amount corresponding to the theoretical total pore volume of the electrolyte holding part and the electrolyte layer, which is calculated from the size (volume) and the porosity of the separator and the electrolyte holding substrate. Was used.

  Thus, the stacked battery shown in FIG. 10 was produced.

[Example 2]
(1) Production of positive electrode element A positive electrode active material slurry was prepared in the same manner as in Example 1.

  As the conductive layer, an aluminum (Al) foil having a thickness of 20 μm and having through holes (hole diameter: 10 μm, porosity of 50%, circular shape) was prepared. The slurry prepared above was applied to one side of the conductive layer and pressed to produce a positive electrode element in which the positive electrode active material layer 15 having a thickness of 70 μm was formed on one side of the conductive layer 25.

(2) Production of negative electrode element A negative electrode active material slurry was prepared in the same manner as in Example 1.

  As the conductive layer, a copper (Cu) foil having a thickness of 20 μm and having a through hole (hole diameter: 10 μm, porosity of 40%, circular shape) was prepared. The slurry prepared above was applied to one side of the conductive layer, pressed, and vacuum dried at 250 ° C., whereby the negative electrode active material layer 12 having a thickness of 30 μm was formed on one side of the conductive layer 25. A negative electrode element was produced.

(3) Production and arrangement of power generation element, impregnation with electrolyte solution A laminated battery shown in FIG. 11 was produced in the same manner as in Example 1 except that the positive electrode element and the negative electrode element produced above were used.

[Example 3]
A laminated battery shown in FIG. 12 was produced in the same manner as in Example 1 except that the negative electrode element produced in Example 2 was used.

(Bipolar battery)
[Example 4]
(1) Production of positive electrode element A positive electrode active material slurry was prepared in the same manner as in Example 1.

  As a conductive layer, an aluminum (Al) foil having a thickness of 20 μm is prepared, and the slurry prepared above is applied to one side of the conductive layer, dried and pressed, so that one side of the conductive layer 45 is formed. A positive electrode element in which a positive electrode active material layer 35 having a thickness of 70 μm was formed was prepared.

(2) Production of negative electrode element A negative electrode active material slurry was prepared in the same manner as in Example 1.

  A copper (Cu) foil having a thickness of 20 μm having through-holes (hole diameter: 10 μm, porosity 40%, circular shape) was prepared as the conductive layer. The slurry prepared above is applied to one side of the conductive layer, dried and pressed, and then vacuum dried at 250 ° C. to form the negative electrode active material layer 32 having a thickness of 30 μm on one side of the conductive layer 45. A negative electrode element was produced.

(3) Preparation of electrolyte solution holding layer and electrolyte layer, impregnation with electrolyte solution Polyethylene oxide (40 parts by mass) and the above electrolyte solution (60 parts by mass) were mixed to obtain a matrix polymer. The gel polymer electrolyte precursor solution was prepared by adding azobisisobutyronitrile (AIBN) as a thermal polymerization initiator corresponding to 5000 ppm by mass to the matrix polymer.

  The separator and the electrolyte holding substrate are immersed in the precursor solution, and the separator and the electrolyte holding substrate are impregnated with the precursor solution for 10 minutes under a vacuum (degree of vacuum: 30 [kPa]) at room temperature (25 ° C.). I let you. As the electrolytic solution holding substrate and the separator, a polyolefin film (material: made of polyethylene (PE), thickness: 10 μm, porosity: 35%) was used as in Example 1.

  And the electrolytic solution holding | maintenance layer and separator with which gel polymer electrolyte was hold | maintained were obtained by heat-processing at 100 degreeC for 2 hours in argon gas atmosphere.

(4) Production of power generation element, sealing with insulating layer And the obtained bipolar electrode, outermost layer positive electrode, and outermost layer negative electrode were cut into a size of 140 mm × 140 mm, and the outer periphery of the cut electrodes (positive electrode and negative electrode) The active material layer formed on the part (20 mm) was peeled off to expose the SUS surface as a current collector. That is, a bipolar electrode, an outermost layer positive electrode, and an outermost layer negative electrode in which the electrode surface was 100 mm × 100 mm and the SUS foil as a current collector was exposed on the outer peripheral part 20 mm of the electrode were obtained. They were immersed in the precursor solution in the same manner as the separator and the electrolyte solution holding material, and impregnated for 10 minutes in a vacuum (degree of vacuum: 30 [kPa]) at room temperature (25 ° C.). Subsequently, the precursor solution of the electrode non-application part was wiped off. Thereafter, a heat treatment was performed at 100 ° C. for 2 hours under an argon gas atmosphere to obtain an electrolyte solution holding layer and a separator in which the gel polymer electrolyte was held. As the electrolyte holding substrate of the separator and the electrolyte holding layer, a substrate cut out to a size of 120 mm × 120 mm was used.

  Next, using a dispenser, the seal precursor was applied to the exposed portion of the SUS foil (the electrode uncoated portion) on the outer periphery of the current collector in the bipolar electrode, the outermost layer positive electrode, and the outermost layer negative electrode. Note that a one-component uncured epoxy resin was used as the seal precursor.

  Next, the positive electrode element, the electrolyte solution holding substrate (electrolyte solution holding portion), and the negative electrode element are laminated so that the conductive layer coated with the seal precursor is completely covered, and the bipolar type coated with the seal precursor. An electrode was obtained. At that time, the conductive layer 45 in the positive electrode element and the conductive layer 45 in the negative electrode element were opposed to each other with the electrolyte solution holding substrate (electrolyte solution holding portion) 46 interposed therebetween. The above procedure was repeated to obtain five bipolar electrodes from five positive electrode elements, five negative electrode elements, and five electrolyte solution holding substrates.

  The five bipolar electrodes, six separators, one positive electrode element, and one negative electrode element produced as described above were laminated using a jig as described below to produce a power generation element. At that time, as shown in FIG. 13, the positive electrode active material layer 35 and the negative electrode active material layer 32 were arranged to face each other with a separator (electrolyte layer) 33 interposed therebetween.

The produced power generation element is hot-pressed for 1 hour under the conditions of a surface pressure of 1 kg / cm ² and 80 ° C. using a hot press machine, so that an uncured seal part (one-part uncured epoxy resin) is obtained. Cured. By this step, the sealing portion can be pressed to a predetermined thickness and cured to form the insulating layer 43. Thereby, a bipolar power generation element in which six layers were laminated was obtained.

(5) Arrangement of power generation element The terminal leads (40, 41) were welded to the outermost conductive layers (31a, 31b) of the power generation element produced above. At this time, the aluminum terminal lead 41 was welded to the conductive layer 31b in the outermost positive electrode element, and the nickel terminal lead 40 was welded to the conductive layer 31a in the outermost negative electrode element. Thereafter, in the same manner as in Example 1, the power generation element was placed in an aluminum laminate film exterior 42 and vacuum sealed to produce a bipolar battery shown in FIG.

  The stacked battery or bipolar battery produced in Examples 1 to 4 has an electrolyte solution holding current collector in which an electrolyte solution holding part composed of a porous polyolefin film is sandwiched between two conductive layers. . Therefore, a sufficient amount of electrolyte can be easily supplied to the electrodes without increasing the distance between the electrodes. In these batteries, since the electrolyte holding current collector exists in the central layer in the power generation element, the electrolytic solution is supplied from the electrolyte holding unit to the active material layer located in the central layer where the lack of the electrolytic solution is likely to occur. It can be supplied quickly and efficiently. Furthermore, since the polyolefin film which is an electrolyte holding substrate is an elastic body, it can function as a buffer layer that absorbs changes in cell thickness accompanying expansion and contraction of the electrode. Furthermore, since a Si material alloyed with lithium is used as the negative electrode active material, a high-capacity battery having a high energy density can be obtained.

  When the conductive layer has holes penetrating in the stacking direction of the electrolyte solution holding current collector as in Example 2 or Example 4, the entire active material layer can be uniformly and quickly passed through the through hole from the electrolyte solution holding unit. An electrolyte can be supplied to the battery.

1 is a schematic cross-sectional view showing a laminated nonaqueous electrolyte secondary battery which is a typical embodiment of the present invention. 1 is a schematic cross-sectional view (a schematic cross-sectional view in a plane parallel to the stacking direction of power generation elements) of an electrolytic solution holding current collector used in a typical embodiment of the present invention. It is a schematic cross section (schematic cross section in a plane parallel to the laminating direction of a power generation element) of an electrolyte solution holding current collector used for other embodiments of the present invention. It is a schematic cross section (schematic cross section in a plane perpendicular to the laminating direction of a power generation element) of an electrolyte solution holding current collector used for other embodiments of the present invention. It is a schematic cross section (schematic cross section in the plane parallel to the laminating direction of a power generation element) of the non-electrolyte holding current collector used for one embodiment of the present invention. It is a schematic cross section (schematic cross section in a plane perpendicular to the laminating direction of a power generation element) of a conductive layer having a through hole that can be used in an embodiment of the present invention. It is a schematic cross section which shows the bipolar non-aqueous electrolyte secondary battery which is other one Embodiment of this invention. It is a perspective view showing an assembled battery obtained by connecting a plurality of stacked batteries according to an embodiment of the present invention. It is a perspective view which shows the assembled battery module which connected the assembled battery by one Embodiment of this invention. It is the schematic of the motor vehicle carrying the assembled battery by one Embodiment of this invention. 1 is a schematic cross-sectional view showing a stacked battery produced in Example 1. FIG. 3 is a schematic cross-sectional view showing a stacked battery produced in Example 2. FIG. 6 is a schematic cross-sectional view showing a stacked battery produced in Example 3. FIG. 6 is a schematic cross-sectional view showing a bipolar battery produced in Example 4. FIG.

Explanation of symbols

10 stacked battery,
11 negative electrode current collector,
11a outermost layer negative electrode current collector,
12, 32 negative electrode active material layer,
13, 33 electrolyte layer,
14 positive electrode current collector,
14a outermost layer positive electrode current collector,
15, 35 positive electrode active material layer,
16, 36 cell layer,
17, 37 Power generation element,
18, 38 Negative electrode tab (terminal),
19, 39 Positive electrode tab (terminal),
20, 40 Negative terminal lead,
21, 41 Positive terminal lead,
22, 42 Exterior body (laminate sheet),
23 negative electrode,
24 positive electrode,
25, 45 conductive layer,
26, 46 Electrolyte holding part,
27 opening,
28 conductive substrate,
29 through holes,
30 Bipolar battery,
31 current collector,
31a The outermost layer current collector on the negative electrode side,
31b The outermost layer current collector on the positive electrode side,
34 Bipolar electrode,
34a, 34b The electrode located in the outermost layer,
43 Insulating layer,
50 battery packs,
51, 52 electrode terminal,
60 battery module,
61, 62 Conductive bar,
70 cars.

Claims (11)

A negative electrode in which a negative electrode active material layer including a negative electrode active material is formed on the surface of a current collector including a conductive layer, an electrolyte layer including a nonaqueous electrolyte, and a positive electrode active material layer including a positive electrode active material are conductive layers. A non-aqueous electrolyte secondary battery including a power generation element having a single battery layer formed by sequentially laminating a positive electrode formed on a surface of a current collector including:
The non-aqueous electrolyte secondary battery, wherein at least one of the current collectors included in the power generation element is an electrolyte solution holding current collector further including an electrolyte solution holding unit for holding an electrolyte solution.   The non-aqueous electrolyte secondary battery according to claim 1, wherein the negative electrode active material includes an element that forms an alloy with lithium.   The non-aqueous electrolyte secondary battery according to claim 1, wherein the electrolyte solution holding current collector has an electrolyte solution holding portion sandwiched between two conductive layers.   The at least one of the conductive layers constituting the electrolytic solution holding current collector has a hole through which the electrolytic solution can penetrate in the stacking direction of the electrolytic solution holding current collector. Non-aqueous electrolyte secondary battery.   The non-aqueous electrolyte secondary battery according to claim 1, wherein the electrolyte solution holding unit is formed of a porous body.   The non-aqueous electrolyte secondary battery according to claim 1, wherein the electrolyte solution holding unit is made of an elastic body.   The non-aqueous electrolyte secondary battery according to claim 1, wherein the electrolyte solution holding current collector is present in a central layer in the power generation element. Producing a power generation element including at least one current collector including a conductive layer and an electrolyte solution holding unit;
Arranging the power generating element inside the exterior body;
Impregnating the electrolytic solution holding part with an electrolytic solution under vacuum; and
The manufacturing method of the nonaqueous electrolyte secondary battery which has this.   An assembled battery using the nonaqueous electrolyte secondary battery according to any one of claims 1 to 7 or the nonaqueous electrolyte secondary battery produced by the production method according to claim 8.   An assembled battery module in which a plurality of assembled batteries according to claim 9 are connected.   The nonaqueous electrolyte secondary battery according to any one of claims 1 to 7, or the nonaqueous electrolyte secondary battery produced by the production method according to claim 8, the assembled battery according to claim 9, or a claim Item 11. A vehicle equipped with the assembled battery module according to Item 10 as a driving power source.

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