JP2010087170A - Electric storage device - Google Patents

Abstract

Provided is an electricity storage device that can stably store an electrode portion therein and can be used in an apparatus or the like to which an external force such as vibration acts.
A plurality of sets of positive electrode plates 3 and negative electrode plates 6 are laminated with a separator 7 interposed therebetween, and an electrode portion 12 into which an electrolytic solution is injected is made of a hard material having a self-shape retaining ability. The terminals 10 and 11 of the positive electrode plate and the negative electrode plate are extended outwardly into a bottomed cylindrical container 20 having an opening 20a having an area larger than the plate surfaces of the positive electrode plate and the negative electrode plate at the top. And the container 20 and the lid 24 have insulating properties with respect to the electrode portions. The electrode portion is pressurized in the direction of compressing in the stacking direction.
[Selection] Figure 1

Description

  The present invention relates to an electricity storage device such as a lithium ion capacitor or a lithium ion secondary battery.

  In recent years, lithium-ion capacitors, which are a type of energy storage device, are capable of rapid charge and discharge and a desired energy capacity even though they are smaller and lighter than conventional batteries. In addition, it is being used in a wide range of fields such as a load leveling device for wind power generation, a voltage sag countermeasure device, a backup power supply device for a hybrid electric vehicle, a fuel cell vehicle, and the like.

  As shown in FIGS. 14 and 15, the conventional lithium ion capacitor generally includes a plurality of positive electrode plates 3 in which positive electrodes 2 are formed on both surfaces of a current collector 1 in an outer package 8 made of a laminate film, and a current collector. A plurality of negative electrode plates 6 having negative electrodes 5 formed on both surfaces of the body 4 are alternately stacked with separators 7 interposed therebetween, and an electrode portion 12 is accommodated therein, and an electrolyte solution 9 is contained therein. Is roughly constructed by injecting and vacuum-sealing.

  Incidentally, the current collector 1 of the positive electrode plate 3 is made of a metal foil having oxidation resistance such as nickel foil or aluminum foil and not chemically eluting, and the both sides are made of a carbon material made of activated carbon or the like. A positive electrode 2 is formed. The current collector 4 of the negative electrode plate 6 is made of a copper foil, and the negative electrode 5 mainly composed of a carbon material is formed on both surfaces thereof.

The separator 7 is made of a sheet material having liquid permeability and non-electron conductivity made of synthetic resin such as polyethylene and polypropylene, glass fiber, and the like. As the electrolyte solution 9, LiBF ₄ , LiPF ₄ , LiClO _{4 are used.} A liquid containing a lithium salt such as LiAsF ₆ is injected.

  Further, the plurality of positive electrode plates 3 are connected to a current collecting tab (terminal) 10 in which the current collectors 1 are external connection terminals, and the current collectors 4 are current collectors of the plurality of negative electrode plates 6. It is connected to a tab (terminal) 11. The outer cover 8 is drawn to the exterior 8 after the current collecting tab 10 and the current collecting tab 11 of the electrode section 12 are extended to the outside, and then the electrode section 12 is drawn. And a sealing portion 14 that surrounds the storage portion 13 is formed.

A configuration of a lithium ion capacitor that is sealed after the electrode portion 12 is housed in such an outer package 8 made of a laminate film and the inside is evacuated is disclosed in, for example, Patent Document 1 below.
Japanese Patent Laid-Open No. 11-86823

  By the way, in the lithium ion capacitor using the laminate sheath 8, the inside of the laminate is evacuated so that the laminate film comes into close contact with both surfaces of the electrode portion 12, and as a result, the positive electrode plate sandwiching the separator 7 in the electrode portion 12 therebetween. 3 and the negative electrode plate 6 have an increased degree of adhesion, so that there is an advantage that the power storage performance can be improved.

  However, on the other hand, the laminate exterior 8 has a low strength and it is difficult to maintain a self-supporting shape, so that it is difficult to hold the internal electrode portion 12 in place when an external force is applied. There was a point. In addition, since the current collecting tabs 10 and 11 extending outward from the laminate exterior 8 are vulnerable to vibration, they may be used in a device that is highly likely to receive strong vibration such as transportation equipment. There was a problem that it was difficult.

  Further, in this type of electricity storage device such as the lithium ion capacitor, gas is generated by decomposition of the internal electrolyte due to overcharge or the like. As a result of this gas being filled inside and expanding the laminate sheath 8, a large deformation occurs, and finally the gas bursts or the gas is ejected or leaks. Is generated.

  For this reason, a power storage device has been proposed in which a sealing jig for the laminate sheath 8 is provided with a cleavage jig that releases an internal gas when the laminate sheath 8 expands as the internal pressure increases. Since the projecting portion is formed on the sealing portion of the electricity storage device by the cleavage jig, the adhesion of the sealing portion is weakened, and there is a possibility that moisture or the like enters and deteriorates.

  The present invention has been made in view of such circumstances, and an electricity storage device that can stably store an electrode portion therein and can also be used in an apparatus or the like to which an external force such as vibration acts. The issue is to provide.

  In order to solve the above problems, the invention described in claim 1 is characterized in that a positive electrode plate having a positive electrode formed on both sides of a current collector and a negative electrode plate having a negative electrode formed on both sides of the current collector are interposed between separators. In an electricity storage device comprising a plurality of sets of electrode layers and an electrolyte portion injected therein, and having positive and negative electrode current collectors connected to the positive and negative electrode collectors, respectively, The electrode part is connected to the terminal from the container in a bottomed cylindrical container made of a hard material having an opening formed on the upper part and having an area larger than the plate surfaces of the positive electrode plate and the negative electrode plate. And the outer peripheral edge of the opening of the container is sealed with a lid, and the container and the lid have the electrodes on the inner peripheral surfaces thereof. When insulation against the part is given In, the electrode portions and is characterized in that pressurized in a direction to compress the lamination direction.

  Here, in the invention described in claim 2, the container is made of an aluminum plate or a steel plate plated with nickel, and the lid is made of an aluminum plate, a steel plate plated with nickel or a laminate film. It is characterized by.

  The invention described in claim 3 is the invention described in claim 1 or 2, wherein an insulating layer made of an insulating material is formed on the inner peripheral surface of the container and the lid. It is characterized by.

  Furthermore, the invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the outer peripheral surface of the container is cleaved when the internal pressure of the container rises above a set value. An explosion-proof valve for discharging the gas is formed.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein at least a portion of the side wall where the terminal does not extend is opposed to the upper part of the electrode part. By extending in this direction, a buffer part for storing gas generated in the container is formed between the extension part of the side wall and the electrode part.

  Here, in the invention described in claim 6, the side wall of the container is extended outward by a portion facing the upper portion of the electrode part, whereby the extension part of the side wall and the electrode part are The buffer portion is formed therebetween, and the explosion-proof valve is formed on a bottom plate portion defining the buffer portion.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the container is formed with a flange projecting in the horizontal direction on the periphery of the opening, and A hole is formed in the part.

  Furthermore, the invention described in claim 8 is characterized in that, in the invention described in any one of claims 1 to 7, cooling fins are integrally disposed on the outer peripheral surface of the container. Is.

  In invention of any one of Claims 1-8, the electrode part which laminated | stacked several positive electrode plates and negative electrode plates on both sides of a separator is a bottomed cylindrical shape which consists of a hard raw material which has self-shape retention ability. Since it is housed in a container and the outer peripheral edge of the opening of the container is sealed with a lid, there is no significant deformation with respect to external force, so the electrode part is stably held inside. Can be kept.

  In addition, since the terminal extending outward from the container can be sandwiched between the container and the lid and firmly fixed, it can be applied to a device that is highly likely to receive strong vibrations such as transportation equipment. It becomes possible to use.

  Furthermore, since an opening having a larger area than the plate surfaces of the positive electrode plate and the negative electrode plate constituting the electrode part is formed in the upper part of the container, the electrode part is preliminarily formed when the power storage device is manufactured. The electrolytic solution can be poured and easily stored in the container through the opening.

  Further, since the container and the lid are pressed in the direction in which the electrode portions are compressed in the stacking direction, the positive electrode plate, the separator, and the negative electrode plate stacked in the inner electrode portions can be brought into close contact with each other. .

In addition, since the inner peripheral surfaces of the container and the lid are provided with insulation against the electrode part, there is no possibility that a short circuit occurs between the electrode part and the container or the lid and the power storage performance is deteriorated. .
Here, in order to provide insulation to the inner peripheral surfaces of the container and the lid, the whole of the container and the lid can be formed of a synthetic resin having insulation.

  On the other hand, such synthetic resins are generally expensive and some of them pass moisture in the air. However, if even a small amount of moisture enters the container, the electrolyte solution is deteriorated. Therefore, as in the invention described in claim 2, an aluminum plate or a nickel-plated steel plate is used as the container, and an aluminum plate, a nickel-plated steel plate or laminate is used as the lid. It is preferable to use a film.

  And when the thing made from a metal is used as the said container and a cover body, in order to provide insulation to each internal peripheral surface, as the invention of Claim 3, the said container and a cover body ( An insulating layer made of a material having an insulating property is formed on the inner peripheral surface of (not required when a laminate film is used). Such an insulating layer is, for example, subjected to insulation treatment with an insulating synthetic resin or the like on its surface, or a container molded with an insulating synthetic resin is disposed inside the inner peripheral surface. Can be formed.

  Moreover, since the said container is formed with the hard raw material which has self-shape holding | maintenance ability, such as a metal and a synthetic resin, like the invention of Claim 4, it can be easily attached to the outer peripheral surface of the said container. An explosion-proof valve can be formed that cleaves and discharges internal gas when the internal pressure rises above a set value.

  Further, according to the invention described in claim 5, the terminal of the container is a side wall from which the terminal does not extend, and at least a part facing the upper part of the electrode part is extended outward, Since the buffer part for storing the gas generated inside is formed between the electrode part and the electrode part, the electrode part is still usable in the initial stage of gas generation even when the explosion-proof valve is formed. In such a case, the gas can be reliably discharged to the outside at a desired time after the gas generation by continuing to use it as it is.

  In addition, if a means for detecting the inflow of gas into the buffer unit is provided in advance, before the gas is finally discharged to the outside, the deterioration of the electrode unit is detected and the power storage device is replaced. Therefore, it is possible to prevent damage to adjacent devices due to gas discharge.

  Here, the buffer portion may be formed over the entire surface between the side wall and the electrode portion by extending the entire side wall facing the electrode portion of the container outward. As described in the invention, the side wall of the container is extended outward only in a portion facing the upper portion of the electrode portion, and is formed only between the extended portion of the side wall and the upper portion of the electrode portion. Is preferred.

  By adopting such a configuration, the electrode portion can be positioned by the lower portion of the side wall. In addition, by preventing the gas accumulated in the upper buffer part from being discharged from an explosion-proof valve formed on the bottom plate part that defines the buffer part, the occurrence of damage to adjacent devices due to the gas discharge can be prevented. Is possible.

  According to the seventh aspect of the present invention, a plurality of power storage devices can be obtained by forming a flange that protrudes in the horizontal direction on the periphery of the opening of the container, and by forming a hole in the flange. When forming the module of the electricity storage device by stacking, it is possible to easily position and fix each other by inserting a fixing rod through the hole.

  Furthermore, as in the invention described in claim 8, heat dissipation can be improved by arranging cooling fins integrally on the outer peripheral surface of the container.

(First embodiment)
1 to 7 show a first embodiment in which the electricity storage device according to the present invention is applied to a lithium ion capacitor and its modification, and the configuration of the electrode unit 12 is shown in FIGS. 14 and 15. Therefore, the same reference numerals are used to simplify the description.

As shown in FIGS. 1-6, in this lithium ion capacitor, the electrode part 12 is accommodated in the hard container 20 which has self-shape retention ability.
The container 20 is made of a metal plate such as an aluminum plate or a nickel-plated steel plate having a plane size somewhat larger than the area of the plate surface of the positive electrode plate 3, the negative electrode plate 6 and the separator 7 of the electrode portion 12, and It is formed into a cylindrical shape with a bottomed cross section by deep drawing so that the depth is slightly shallower than the laminated thickness of the electrode portion 12.

  Thus, a rectangular opening 20 a having a larger area than the plate surfaces of the positive electrode plate 3, the negative electrode plate 6 and the separator 7 is formed in the upper part of the container 20. Further, a flange 21 having a predetermined width dimension is formed on the entire periphery of the periphery of the opening 20a.

  Further, the inner peripheral surface of the container 20 is provided with insulation with respect to the electrode portion 12. Here, as a specific configuration for imparting insulation to the inner circumferential surface, for example, the container 20 shown in FIG. 4 has insulation on the inner circumferential surface as shown in FIG. 5A. The insulating property can be imparted by coating the synthetic resin to form the insulating layer 22.

  As another specific configuration, as shown in FIG. 5 (b), a bottomed rectangular cylindrical insulating container formed of an insulating synthetic resin along the inner peripheral surface of the container 20. By disposing 23, the above insulating properties can be imparted. Incidentally, the insulating container 23 can be formed by injection molding.

  Then, the electrode part 12 into which the electrolytic solution has been poured in advance in the insulating layer 22 or the insulating container 23 in the container 20 is connected to the current collecting tab terminals 10 and 11 from the flange part 21 on the short side of the container 20. While being housed in a state of extending outward, the opening 20a is sealed by the lid 24.

  The lid body 24 is formed by forming a metal plate such as an aluminum plate similar to the container 20 or a nickel-plated steel plate into a rectangular plate shape having the same dimensions as the outer dimensions of the flange portion 21 of the container 20. . An insulating layer is also formed on the inner peripheral surface of the lid 24. In addition, about the cover body 24, it can replace with the metal plate mentioned above, and can also use a laminate film.

  And the opening part 20a of the container 20 is sealed by the outer peripheral part 24a facing the collar part 21 of the container 20 of the cover body 24 being fixed to the container 20 by welding or the like. At this time, the lid body 24 is fixed to the container 20 in a state where a pressing force for compressing the electrode portion 12 in the stacking direction is applied.

  FIG. 7 shows a modification of the first embodiment. When gas is generated in the container 20 on the lower surface of the flange portion 21 of the container 20, the internal pressure rises to a set value or more. The explosion-proof valve 25 is formed by discharging the internal gas by being cleaved by the internal pressure.

  In the lithium ion capacitor having the above configuration, the electrode part 12 is housed in a bottomed cylindrical container 20 made of aluminum or the like and having a self-shape retaining ability, and the opening 20a of the container 20 is formed in the flange part 21. Since it is sealed by the lid 24, there is no significant deformation with respect to the external force, so that the electrode part 12 can be stably held inside. In addition, it becomes possible to more reliably prevent moisture from entering from the outside during normal times.

  In addition, since the current collecting tabs 10 and 11 extending outward from the container 20 can be sandwiched between the container 20 and the lid 24 and firmly fixed, it receives strong vibrations from transportation equipment and the like. It can also be used for highly probable devices.

  Further, since the opening 20a of the container 20 is formed in an area wider than the plate surfaces of the positive electrode plate 3, the negative electrode plate 6 and the separator 7 constituting the electrode unit 12, as shown in FIG. When manufacturing an ion capacitor, as shown to the figure (a), electrolyte solution can be poured beforehand into the electrode part 12, and it can accommodate in the inside of the container 20 from the opening part 20a easily.

  Further, since the container 20 and the lid body 24 are pressed together in the direction in which the electrode portions 12 are compressed in the laminating direction, the positive electrode plate 3, the separator 7 and the negative electrode plate 6 laminated in the internal electrode portion 12 are arranged. The power storage efficiency can be increased by the close contact.

  In addition, since insulation is ensured on the inner peripheral surfaces of the container 20 and the lid 24 by the insulating layer 22 or the insulating container 23, a short circuit occurs between the electrode portion 12 and the container 20 or the lid 24. Therefore, there is no risk of deteriorating power storage performance.

  Further, according to the modification shown in FIG. 7, the explosion-proof valve 25 is opened when the pressure in the container 20 rises due to decomposition of the electrolyte in the container 20 due to overcharge or the like to generate gas. Thus, the internal gas can be discharged smoothly. In particular, since the explosion-proof valve 25 is formed on the lower surface of the flange portion 21, it is possible to prevent the adjacent apparatus from being damaged when the gas is discharged.

(Second Embodiment)
8 to 10 show a second embodiment of the present invention. Similarly, the same components as those shown in FIGS. 1 to 7 are denoted by the same reference numerals.
In the lithium ion capacitor of the present embodiment, the portion 30a facing the upper portion of the electrode portion 12 of the side wall 30 on the long side where the current collecting tabs 10 and 11 of the container 20 are not extended is extended outward. A buffer portion 31 for storing gas generated in the container 20 is formed between the extended portion 20 a and the electrode portion 12.

  Accordingly, a bottom plate portion 32 that forms the bottom portion of the buffer portion 31 is formed between the side wall 30 and the extending portion 30a. An explosion-proof valve 25 is formed on the lid 24 located above the bottom plate portion 32 or the buffer portion 32.

  Also with the lithium ion capacitor having the above configuration, in addition to obtaining the same operational effects as those of the first embodiment, a portion of the side wall 30 of the container 20 facing the upper portion of the electrode portion 12 is extended outward. Since the buffer portion 31 for storing the gas generated inside is formed between the extended portion 30a and the electrode portion 12, the electrode portion 12 can still be used in the early stage of gas generation. If it is in a state, it can be continuously used as it is, and the gas can be reliably discharged to the outside at a desired time after the gas is generated.

  Further, if a means for detecting the inflow of gas into the buffer 31 is provided in advance, the lithium ion capacitor is detected by detecting deterioration of the electrode 12 before the gas is finally discharged to the outside of the container 20. Thus, it is possible to prevent damage to adjacent devices due to gas discharge.

  In addition, only the portion 30 a of the side wall 30 of the container 20 facing the upper portion of the electrode portion 12 is extended outward, and the buffer portion 31 is provided only between the extended portion 30 a of the side wall 30 and the upper portion of the electrode portion 12. Since it is formed, the electrode part 12 can be positioned by the lower part of the side wall 30.

(Third embodiment)
FIG. 11 shows a third embodiment of the present invention. The difference from the first embodiment is that the upper and lower surfaces (FIG. 11 (a)) of the flange portion 21 of the container 20 or This is because a plurality of cooling fins 35 are provided on the bottom surface of the flange 21 (FIG. 11B).

  As a result, according to the lithium ion capacitor having the above configuration, it is possible to improve the heat dissipation from the lithium ion capacitor even when used in a high temperature atmosphere.

(Fourth embodiment)
FIGS. 12 and 13 show a fourth embodiment of the present invention. In this lithium ion capacitor, as shown in FIG. 12, holes are respectively formed at the four corners of the flange portion 21 of the container 20. 36 is drilled.

  Thus, according to the lithium ion capacitor, as shown in FIG. 13, when a module is formed by stacking a plurality of lithium ion capacitors, the fixing rod 37 is inserted into the hole 36 so that the lithium ion capacitor is By stacking, mutual positioning and fixing can be easily performed. Further, when such a module is configured, a pressing force in the compression direction is easily applied to the lithium ion capacitors positioned above and below, so that a pressing force in the stacking direction is easily applied to the internal electrode portion 12. be able to.

  In each of the first to fourth embodiments, the case where the electricity storage device according to the present invention is applied only to a lithium ion capacitor has been described. However, the present invention is not limited to this. For example, a lithium ion secondary For other power storage devices including an electrode part into which an electrolyte containing a lithium salt is injected between a positive electrode plate and a negative electrode plate, which are arranged to face each other via a separator, such as a battery, The same can be applied.

It is a longitudinal cross-sectional view which shows the 1st Embodiment of this invention. It is a top view of FIG. It is the top view seen in the XX line of FIG. It is a longitudinal cross-sectional view of the container of FIG. 4 shows a state in which insulation is imparted to the inner peripheral surface of the container of FIG. 4, (a) is a longitudinal sectional view when an insulating layer is formed on the outer peripheral surface, and (b) is an insulating container along the inner peripheral surface. It is a longitudinal cross-sectional view at the time of mounting | wearing. It is a longitudinal cross-sectional view which shows the assembly order of the lithium ion capacitor of FIG. It is a longitudinal cross-sectional view of the short side direction which shows the modification of FIG. It is a longitudinal cross-sectional view of the short side direction which shows the 2nd Embodiment of this invention. It is a top view of FIG. It is the top view seen in the YY line of FIG. It is a longitudinal cross-sectional view which shows the 3rd Embodiment of this invention. It is a top view which shows the 4th Embodiment of this invention. It is a front view which shows the state which laminated | stacked the several lithium ion capacitor shown in FIG. 12, and formed the module. It is a longitudinal cross-sectional view which shows the conventional lithium ion capacitor. FIG. 15 is a plan view of FIG. 14.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Current collector on the positive electrode side 2 Positive electrode 3 Positive electrode plate 4 Current collector on the negative electrode side 5 Negative electrode 6 Negative electrode plate 7 Separator 10 Current collector tab (terminal) on the positive electrode side
11 Negative current collector tab (terminal)
DESCRIPTION OF SYMBOLS 12 Electrode part 20 Container 20a Opening part 21 Gutter part 22 Insulating layer 23 Insulating container 24 Cover body 25 Explosion-proof valve 30 Side wall 30a Side wall extension part 31 Buffer part 32 Bottom plate part 35 Fin 36 Hole part

Claims (8)

A plurality of sets of a positive electrode plate having a positive electrode formed on both sides of a current collector and a negative electrode plate having a negative electrode formed on both sides of the current collector are stacked with a separator interposed therebetween, and an electrolyte is injected. In an electricity storage device comprising an electrode portion and having positive and negative electrode terminals connected to the positive and negative electrode current collectors,
The electrode portion is connected to the terminal in a bottomed cylindrical container made of a hard material having a self-shape retaining ability and having an opening having an area larger than the plate surface of the positive electrode plate and the negative electrode plate on the upper portion. Is stored in a state of extending outward from the container, and the outer peripheral edge of the opening of the container is sealed by a lid,
In addition, the container and the lid body are provided with insulating properties on the inner peripheral surfaces thereof with respect to the electrode portions, and are pressurized in a direction to compress the electrode portions in the stacking direction. Power storage device.   2. The electricity storage device according to claim 1, wherein the container is made of an aluminum plate or a nickel-plated steel plate, and the lid is made of an aluminum plate, a nickel-plated steel plate or a laminate film. .   The electric storage device according to claim 1 or 2, wherein an insulating layer made of an insulating material is formed on inner peripheral surfaces of the container and the lid.   4. An explosion-proof valve is formed on the outer peripheral surface of the container, and an explosion-proof valve is formed for cleaving and discharging the internal gas when the internal pressure of the container rises above a set value. The electricity storage device described in 1.   In the container, the container is extended between the extended portion of the side wall and the electrode portion by extending at least a portion of the side wall from which the terminal does not extend to the upper portion of the electrode portion. A power storage device according to any one of claims 1 to 4, wherein a buffer section for storing gas generated therein is formed.   As for the side wall of the container, the buffer portion is formed between the extended portion of the side wall and the electrode portion by the portion facing the upper portion of the electrode portion extending outward, and the buffer portion is formed. 6. The electricity storage device according to claim 5, wherein the explosion-proof valve is formed on a bottom plate portion defining the buffer portion.   7. The container according to any one of claims 1 to 6, wherein a ridge that protrudes in a horizontal direction is formed at a peripheral edge of the opening, and a hole is formed in the ridge. Power storage device.   The electricity storage device according to any one of claims 1 to 7, wherein cooling fins are integrally disposed on an outer peripheral surface of the container.

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