JP2013123006A - Lithium ion capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lithium ion capacitor which makes an energy capacity less likely to decrease and achieves large charge/discharge capacities.SOLUTION: A lithium ion capacitor includes: positive electrodes; negative electrodes; and separators, each of which is disposed between the positive electrode and the negative electrode, and an electrode laminated body formed by laminating the positive electrodes, the negative electrodes, and the separators is housed in a case. The case is filled with an organic electrolyte including lithium ions. At least one of an upper surface and a bottom surface of the case is composed of a plate body having a flat plate like first surface 61Aincluding an outer edge, a second surface 61Apositioned at the inner side of the first surface and having elasticity, and a flat plate like third surface 61Apositioned at the inner side of the second surface.

Description

The present invention relates to a lithium ion capacitor.

In recent years, with the growing awareness of resource saving and environmental issues, development of power storage devices has been promoted.
In particular, in storage systems for clean energy such as solar power generation or wind power generation, and power storage systems such as power sources for electric vehicles or hybrid electric vehicles, an energy storage device that has a large energy capacity and that can be rapidly charged and discharged is required. It is said.

As one of such power storage devices, a lithium ion secondary battery using a carbon material such as graphite as a negative electrode and a lithium-containing metal oxide such as LiCoO ₂ as a positive electrode has been put into practical use.
A lithium ion secondary battery is distinguished from a lithium battery using lithium metal because only lithium ions are involved in charging and discharging without using metallic lithium for the negative electrode, and has a feature of high voltage and high capacity.

In addition, non-aqueous power storage devices are attracting attention, and as one of them, lithium ion capacitors that combine the power storage principles of lithium ion secondary batteries and electric double layer capacitors have been proposed.
A lithium ion capacitor (hereinafter also referred to as a cell) uses a material capable of occluding and releasing lithium ions as a negative electrode material, and occupies and supports lithium ions in the negative electrode (hereinafter referred to as “occlusion and support”). In other words, the negative electrode potential is lowered. As a result, the cell voltage can be increased and the energy capacity can be increased.

Patent Document 1 includes a positive electrode made of a carbon material, a negative electrode made of a material capable of occluding and releasing lithium ions, and a separator interposed between the negative electrode and the positive electrode. A non-aqueous electricity storage device is disclosed in which an electrode laminate formed by laminating the separator is accommodated in a case, and an organic electrolyte containing lithium ions is injected into the case.
In the non-aqueous power storage device described in Patent Document 1, the case is a box having an upper opening and a lower opening, and a hard case body surrounding the side surface of the electrode laminate, and the case body. A lower lid that is separately manufactured and joined to the case body so as to close the lower opening, and an upper lid that is made separately from the case body and joined to the case body so as to close the upper opening. It is characterized by being.

JP 2008-300593 A

In the non-aqueous storage device (lithium ion capacitor) described in Patent Document 1, lithium ions are doped in advance in the negative electrode (hereinafter, “pre-doping” is also referred to as “pre-doping”). Specifically, a lithium metal foil is disposed in the cell, and lithium ions are doped into the negative electrode by electrochemical contact with the lithium metal.

When the negative electrode is doped with lithium ions, the lithium metal foil disappears, and accordingly, the volume of the contents in the cell decreases.
However, since the non-aqueous electricity storage device described in Patent Document 1 has a structure in which an upper lid and a lower lid are joined to a case body, a gap is formed in a portion occupied by the lithium metal foil. As a result, the electrode stack cannot be pressed firmly with the upper lid or lower lid of the case, resulting in an increase in the distance between the electrodes, resulting in a decrease in energy capacity and a longer electrolyte distance required for lithium ion conduction. Therefore, the charge / discharge capacity is considered to be small.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a lithium ion capacitor that has a low energy capacity and a large charge / discharge capacity.

The lithium ion capacitor of the present invention is
A positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and an electrode laminate formed by stacking the positive electrode, the negative electrode, and the separator is contained in a case, and lithium is contained in the case. A lithium ion capacitor into which an organic electrolyte containing ions is implanted,
At least one surface of the upper surface and the bottom surface of the case is a flat plate-like first surface including an outer edge, a second surface having elasticity, located on the inner side of the first surface, and positioned on the inner side of the second surface. It consists of a plate-shaped body having a flat plate-like third surface.

In the lithium ion capacitor of the present invention, at least one of the upper surface and the bottom surface of the case has a flat plate-shaped first surface including an outer edge, an elastic second surface located on the inner side of the first surface, and It consists of a plate-like body having a flat plate-like third surface located inside the second surface.
As described above, when the elastic second surface is provided on the plate-like body, the third surface of the plate-like body can be pressed against the electrode by the elastic action of the second surface of the plate-like body.

Therefore, even if the volume of the contents in the cell is reduced by doping lithium ions, the third surface of the plate is pressed against the electrode by pressing the third surface of the plate to the volume in the cell. Follow changes. As a result, the distance between the electrodes can be kept narrow, so that the battery volume can be reduced and the reduction in energy capacity can be prevented. Moreover, since the moving distance of lithium ions in the electrolytic solution can be reduced, the charge / discharge capacity can be increased.

In the lithium ion capacitor of the present invention, it is preferable that a bellows-like elastic portion is provided on the second surface.
The bellows-like elastic part can be formed, for example, by press-molding a plate-like body. Such an accordion-like elastic portion can be formed by being drawn thinner than the original thickness by press molding. By such press molding, the second surface is work-cured and has appropriate elasticity. For this reason, the 2nd surface which has elasticity in a plate-shaped object can be formed. Therefore, the effect of the present invention for pressing the above-described electrode can be sufficiently exhibited.

In the lithium ion capacitor of the present invention, it is preferable that the bellows-like elastic portion is provided along the outline of the first surface.
When the bellows-like elastic portion is provided along the contour of the first surface, the third surface of the plate-like body can be varied along the contour of the first surface. Therefore, since the volume can be changed while the third surface and the first surface are kept parallel, the electrodes can be kept parallel and the battery performance can be made uniform within the surface of the electrodes.

In the lithium ion capacitor of the present invention, it is preferable that an extending portion is provided further outside the first surface.
When the extending portion is provided further outside the first surface, the plate-like body has high rigidity due to the bent portion formed between the first surface and the extending portion. Therefore, even when a force is applied to the lithium ion capacitor, a local force is hardly applied between the plate-like body and another plate-like body or a frame-like body described later, and it is difficult to peel off at the joint portion.

In the lithium ion capacitor of the present invention, the case further includes a box-like body having an upper opening and a lower opening and a frame-like body surrounding the side surface of the electrode laminate, and the first of the plate-like body. It is preferable that the end of the surface is joined to the frame-like body so as to close the upper opening or the lower opening of the frame-like body.
When the case includes the frame-like body, the electrode laminate can be firmly pressed by the third surface of the plate-like body while fixing the first surface of the plate-like body to the frame-like body. Moreover, since the frame-like body has a thickness, the electrolyte solution inlet can be easily formed. Therefore, it is easy to inject electrolyte.
Furthermore, the strength of the entire lithium ion capacitor can be improved by providing the case with a frame-like body.

In the lithium ion capacitor of the present invention, the frame body preferably has at least an insulating portion.
If the frame-like body has an insulating portion, it is possible to prevent a short circuit even if the plate-like body is charged.

In the lithium ion capacitor of the present invention, the plate-like body is preferably made of metal.
When the plate-like body is made of metal, heat generated inside the cell can be quickly diffused to the outside.

In the lithium ion capacitor of the present invention, in the cross section perpendicular to the upper surface of the case, the third surface of the plate-like body is closer to the electrode laminate than the first surface of the plate-like body. Is preferred.
In this case, the electrode stack can be more reliably pressed by the third surface of the plate-like body.

The case of the present invention is used for the lithium ion capacitor of the present invention.

FIG. 1 is a cross-sectional view schematically showing an example of a lithium ion capacitor according to the first embodiment of the present invention. FIG. 2 is a perspective view schematically showing an example of the lithium ion capacitor according to the first embodiment of the present invention. FIG. 3 is a perspective view schematically showing a frame body of a case constituting the lithium ion capacitor shown in FIGS. 1 and 2. FIG. 4A is a plan view schematically showing a first plate-like body of the case constituting the lithium ion capacitor shown in FIGS. 1 and 2. FIG. 4B is a cross-sectional view of the first plate-like body shown in FIG. FIG. 5 is a cross-sectional view schematically showing another example of the first plate-like body of the case constituting the lithium ion capacitor according to the first embodiment of the present invention. FIG. 6 is a cross-sectional view schematically showing still another example of the first plate-like body of the case constituting the lithium ion capacitor according to the first embodiment of the present invention. FIG. 7 is a cross-sectional view schematically showing still another example of the first plate-like body of the case constituting the lithium ion capacitor according to the first embodiment of the present invention. FIG. 8 is a cross-sectional view schematically showing another example of a case constituting the lithium ion capacitor according to the first embodiment of the present invention. FIG. 9A is a cross-sectional view schematically showing an example of a lithium ion capacitor before lithium ion pre-doping, and FIG. 9B shows a lithium ion capacitor after completion of lithium ion pre-doping. It is sectional drawing which shows an example typically. FIG. 10 is a perspective view schematically showing an example of a lithium ion capacitor according to the second embodiment of the present invention. 11 is a cross-sectional view schematically showing a case constituting the lithium ion capacitor shown in FIG. FIG. 12 is a perspective view schematically showing another example of the lithium ion capacitor according to the second embodiment of the present invention. 13 is a cross-sectional view schematically showing a case constituting the lithium ion capacitor shown in FIG. FIG. 14 is a perspective view schematically showing still another example of the lithium ion capacitor according to the second embodiment of the present invention. 15 is a cross-sectional view schematically showing a case constituting the lithium ion capacitor shown in FIG.

Hereinafter, embodiments of the present invention will be specifically described. However, the present invention is not limited to the following embodiments, and can be applied with appropriate modifications without departing from the scope of the present invention.

(First embodiment)
Hereinafter, a first embodiment which is an embodiment of a lithium ion capacitor of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing an example of a lithium ion capacitor according to the first embodiment of the present invention.
FIG. 2 is a perspective view schematically showing an example of the lithium ion capacitor according to the first embodiment of the present invention.
1 is a cross-sectional view taken along line AA of the lithium ion capacitor shown in FIG.

In the lithium ion capacitor 100 shown in FIG. 1, an electrode laminate 50 formed by laminating a positive electrode 10, a negative electrode 20, and a separator 40 is accommodated in a case 60A. A lithium electrode 30 is also accommodated in the case 60A.

In the present specification, the “positive electrode” means a pole on the side from which a current flows out during discharging and into which a current flows during charging. In addition, the “negative electrode” means a pole on the side where a current flows in during discharge and a current flows out in charging.

As shown in FIGS. 1 and 2, the case 60A includes a first plate 61A provided on the upper surface of the case 60A, a second plate 62A provided on the bottom of the case 60A, and a frame shape. And a body 63A.
An organic electrolyte containing lithium ions (hereinafter also referred to as an electrolytic solution) is injected into the case 60A.
Hereinafter, in the present specification, when there is no need to particularly distinguish the first plate-like body and the second plate-like body, they are simply referred to as a plate-like body.

The positive electrode terminal 16 is provided between the first plate-like body 61A and the frame-like body 63A, for example. As shown in FIGS. 1 and 2, the positive terminal 16 extends outward from the outer periphery of the case 60A.
A positive electrode lead 18 is electrically connected to the positive electrode terminal 16. The positive electrode lead 18 can electrically connect the positive electrode terminal 16 and the positive electrode current collector 12 of the positive electrode 10. Examples of the material of the positive electrode terminal 16 and the positive electrode lead 18 include aluminum and stainless steel.

The negative electrode terminal 26 is provided between the first plate-like body 61A and the frame-like body 63A, for example, apart from the positive electrode terminal 16. As shown in FIGS. 1 and 2, the negative electrode terminal 26 extends outward from the outer periphery of the case 60A.
A negative electrode lead 28 is electrically connected to the negative electrode terminal 26. The negative electrode lead 28 can electrically connect the negative electrode terminal 16 and the negative electrode current collector 22 of the negative electrode 20. Examples of the material of the negative electrode terminal 26 and the negative electrode lead 28 include copper, stainless steel, nickel, and the like.

In FIGS. 1 and 2, the positive terminal 16 is provided at the left end (one end) of the case 60A, and the negative terminal 26 is provided at the right end (the other end) of the case 60A. Although provided, the positions of the positive terminal 16 and the negative terminal 26 are not particularly limited.

The negative electrode lead 28 can further electrically connect (short-circuit) the lithium current collector 32 of the lithium electrode 30 and the negative electrode current collector 22 of the negative electrode 20.
With such a configuration, when the electrolytic solution is injected and sealed in the case 60A and left for a predetermined time (for example, 10 days), the lithium foil 34 of the lithium electrode 30 is dissolved in the electrolytic solution. It can be lithium ion. As a result, lithium ions can be electrochemically doped (also referred to as pre-doping) into the negative electrode 20 via the electrolytic solution. As a result, the potential of the negative electrode 20 can be lowered.

The lithium foil 34 is completely dissolved in the electrolytic solution by pre-doping, for example. In FIG. 1, for convenience, the illustration of the electrolytic solution is omitted, and the lithium foil 34 before being dissolved in the electrolytic solution is illustrated.

The electrode laminate 50 is accommodated in the case 60A and immersed in the electrolytic solution.
In the example illustrated in FIG. 1, the electrode stack 50 includes the separator 40, the negative electrode 20, the positive electrode 10, the negative electrode 20, the positive electrode 10, the negative electrode 20, the lithium electrode 30, and the separator 40 from the bottom surface inside the second plate-like body 62 </ b> A. And the separator 40 is interposed between the poles. That is, in the example shown in FIG. 1, the electrode stack 50 includes the two layers of the positive electrode 10 and the three layers of the negative electrode 20, but the number thereof is not particularly limited. Each of the positive electrode 10 and the negative electrode 20 may have about 10 layers. Similarly, the number and location of the lithium electrodes 30 are not particularly limited. The positive electrode 10, the negative electrode 20, the lithium electrode 30, and the separator 40 have a sheet-like shape.

In addition, the form of the electrode laminated body 50 is not limited to the example shown in FIG. 1, For example, the laminated sheet is formed by laminating the positive electrode, the negative electrode, the lithium electrode, and the separator, and the laminated sheet is wound. It may be a structure.

Hereinafter, the case 60 </ b> A for housing the electrode stack 50 will be described.
FIG. 3 is a perspective view schematically showing a frame body of a case constituting the lithium ion capacitor shown in FIGS. 1 and 2.
The frame-like body 63A has a rectangular box shape in plan view having an upper opening and a lower opening. When the electrode stack 50 is accommodated, the side surface of the electrode stack 50 is entirely surrounded by the frame-shaped body 63A.

Moreover, the recessed part 73 for fixing the positive electrode terminal 16 and the negative electrode terminal 26 may be provided like the frame-shaped body 63A shown in FIG.
As described above, the positions of the positive terminal 16 and the negative terminal 26 are not particularly limited. Therefore, for example, an opening may be provided in the frame-like body instead of the recess, and the positive terminal 16 and the negative terminal 26 may protrude outward from the opening.
Further, a frame-like body may be constituted by a plurality of members, and the positive electrode terminal 16 and the negative electrode terminal 26 may be protruded outward from between the members.

In the lithium ion capacitor according to the first embodiment of the present invention, as a constituent material of the frame-like body, any conventionally known material can be used as long as it is somewhat hard. For example, it can be arbitrarily selected from resin materials, metal materials, ceramic materials, and the like.
As examples of the resin material, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyimide (PI), fluorine resin, and the like can be used. As an example of the metal material, aluminum, stainless steel, or the like can be preferably used.

In the first embodiment of the present invention, the frame body preferably has at least an insulating portion.
Therefore, it is preferable to use a resin material or a ceramic material as a constituent material of the frame-like body. Further, a metal material coated with an insulating film may be used as a constituent material of the frame-like body.
If the frame-like body has an insulating portion, it is possible to prevent a short circuit even if the plate-like body is charged.

Such a frame-like body can be produced, for example, by using a metal material as a molding material and press molding (for example, impact molding) using a metal mold. Alternatively, a frame material may be produced by using a resin material as a molding material and injection molding the resin material.

As shown in FIGS. 1 and 2, the end portion of the first plate-like body 61A formed in a rectangular shape is joined to the upper surface side of the frame-like body 63A by an adhesive, welding, welding, or the like, The upper opening of the frame-shaped body 63A is closed. Further, the end of the second plate-shaped body 62A formed in a rectangular shape is joined to the lower surface side of the frame-shaped body 63A by an adhesive, welding, welding, or the like, so that the lower opening of the frame-shaped body 63A is opened. Is blocking.
In addition, when joining the edge part of a plate-shaped object with a frame-shaped object with an adhesive agent, it is preferable that the said adhesive agent is insoluble in the solvent of an organic electrolyte.

In the lithium ion capacitor according to the first embodiment of the present invention, at least one of the upper surface and the bottom surface of the case is located on the flat plate-like first surface including the outer edge and the inner side of the first surface, and is elastic. It consists of the plate-shaped body which has the 2nd surface which has, and the flat 3rd surface located inside the said 2nd surface.

FIG. 4A is a plan view schematically showing a first plate-like body of the case constituting the lithium ion capacitor shown in FIGS. 1 and 2. FIG. 4B is a cross-sectional view of the first plate-like body shown in FIG.

The first plate member 61A shown in FIG. 4 (a) and 4 (b), the first surface 61A ₁ tabular comprising an outer edge, located inside of the first surface 61A _1, having an elastic It has a second surface 61A _2, and a third surface 61A ₃ tabular located inside of the second surface 61A _2.
The second surface 61A ₂ of the first plate-shaped member 61A, bellows-shaped elastic portion 71A is provided.

In the present specification, the “bellows-like elastic portion” refers to a portion having a folded structure.
In the first plate-like body 61A shown in FIGS. 4A and 4B, the bellows-like elastic portion 71A has a folded structure of three mountain folds and three valley folds.
Bellows-shaped elastic portion 71A is to have a resilient surface the bellows-shaped elastic portion 71A is provided, the second surface 61A ₂ having elasticity.
In addition, the number and shape of the mountain fold and the valley fold of the bellows-like elastic part are not particularly limited.

In the lithium ion capacitor according to the first embodiment of the present invention, the bellows-like elastic portion is preferably provided along the outline of the first surface of the plate-like body.
When the bellows-like elastic portion is provided along the outline of the first surface, the volume can be changed while the third surface and the first surface are maintained in parallel, so that the electrode is maintained in parallel and the electrode The battery performance can be made uniform in the plane.

In the example shown in FIG. 4A, the outline of the first surface is rectangular in plan view, but the corner may have a curvature or chamfer.
Further, as in the example shown in FIG. 4A, the corners of the bellows-like elastic part preferably have a curvature, but the corners of the bellows-like elastic part do not have a curvature. Also good.

In the lithium ion capacitor according to the first embodiment of the present invention, an extending portion may be provided on the outer side of the first surface of the plate-like body.
When the extending portion is provided further outside the first surface, the plate-like body has high rigidity due to the bent portion formed between the first surface and the extending portion. Therefore, even when a force is applied to the lithium ion capacitor, a local force is hardly applied between the plate-like body and the frame-like body, and separation at the joint portion can be prevented.

FIG. 5 is a cross-sectional view schematically showing another example of the first plate-like body of the case constituting the lithium ion capacitor according to the first embodiment of the present invention.
On the further outer side of the first surface of the first plate-like body 61B shown in FIG. 5, an extending portion 72B along the frame-like body 63B is provided.
Other configurations of the first plate-like body 61B are the same as the configurations of the first plate-like body 61A shown in FIGS. 4A and 4B, although the shape of the bellows-like elastic portion 71B is slightly different. It is.

In the lithium ion capacitor according to the first embodiment of the present invention, the shape of the extending portion is not particularly limited as long as it is provided further outside the first surface of the plate-like body.
For example, a shape in which extending portions parallel to the first surface and the third surface of the first plate-like body 61B are provided on the outer side of the extending portion 72B shown in FIG.

In the lithium ion capacitor according to the first embodiment of the present invention, the shape of the bellows-like elastic portion is not particularly limited.
6 and 7 are cross-sectional views schematically showing still another example of the first plate-like body of the case constituting the lithium ion capacitor according to the first embodiment of the present invention.
The bellows-like elastic portion 71C provided on the second surface of the first plate-like body 61C shown in FIG. 6 has a folded structure of two mountain folds and two valley folds. The bellows-like elastic portion 71C has a surface parallel to the first surface and the third surface of the plate-like body 61C.
The bellows-like elastic part 71D provided on the second surface of the first plate-like body 61D shown in FIG. 7 has a folded structure of two round folds and two valley folds.
The first plate-like body 61C shown in FIG. 6 and the first plate-like body 61D shown in FIG. 7 are provided with extended portions, but the extended portions are not provided. Good.

As shown in FIGS. 4A, 4B, 5, 6, and 7, the lithium ion capacitor according to the first embodiment of the present invention has a plate in a cross section perpendicular to the upper surface of the case. It is preferable that the 3rd surface of a cylindrical body exists in the position nearer to an electrode laminated body than the 1st surface of a plate-shaped body.
In this case, the electrode stack can be more reliably pressed by the third surface of the plate-like body.
For example, when the thickness of the electrode laminate is 7 mm, the third surface of the plate-like body is 0.5 to 1.0 mm (the thickness of the electrode laminate is 7 to 14%) from the first surface of the plate-like body. Equivalent) It is preferable that it is in a position close to the electrode laminate.

The configuration of the first plate-like body has been described so far, but the second plate-like body is also the first plate shown in FIGS. 4 (a), 4 (b), 5, 6, and 7. It can have the same configuration as the plate-like body.
In the lithium ion capacitor according to the first embodiment of the present invention, the configuration of the bellows-like elastic portion of the first plate-like body is the same as the configuration of the bellows-like elastic portion of the second plate-like body. Although it is preferable, there may be different configurations.

In the lithium ion capacitor according to the first embodiment of the present invention, when at least one of the upper surface and the bottom surface of the case has a second surface having elasticity, the area of the first surface, the second surface, and the third surface The ratio of the area of the second surface to the total is preferably 5 to 30%.
If the ratio of the area of the second surface is less than 5%, there are too few portions having elasticity, and it becomes difficult for the plate-like body to follow the volume change in the cell. On the other hand, if the ratio of the area of the second surface exceeds 30%, the area of the third surface that holds the electrode cannot be increased. For this reason, it becomes difficult to hold down the whole electrode, and it becomes difficult to make the battery performance uniform in the electrode surface.

In the lithium ion capacitor according to the first embodiment of the present invention, the area of the third surface is preferably equal to the area of the electrode stack or larger than the area of the electrode stack.

1 and 2, both the first plate-like body 61A and the second plate-like body 62A are provided with bellows-like elastic portions, that is, both have a second surface having elasticity. An example is shown.
However, in the lithium ion capacitor according to the first embodiment of the present invention, one of the first plate member and the second plate member may not have the second surface having elasticity.
FIG. 8 is a cross-sectional view schematically showing another example of a case constituting the lithium ion capacitor according to the first embodiment of the present invention.
In the case 60E shown in FIG. 8, the first plate-like body 61E and the frame-like body 63E have the same configuration as the first plate-like body 61A and the frame-like body 63A in the case 60A shown in FIGS. doing. On the other hand, the second plate-like body 62E is not provided with a second surface that is extendable.

In the lithium ion capacitor according to the first embodiment of the present invention, any conventionally known material can be used as the constituent material of the plate-like body. For example, it can be arbitrarily selected from resin materials, metal materials, ceramic materials, and the like.
However, it is preferable to use a metal material or a resin material that easily obtains elasticity as a constituent material of the plate-like body having the elasticity on the second surface.

In particular, it is preferable to use a metal material as a constituent material of the plate-like body.
When the plate-like body is made of metal, heat generated inside the cell can be quickly diffused to the outside.
As an example of the metal material, aluminum, an aluminum alloy, stainless steel, copper, or the like can be suitably used.

The plate-like body before forming the second surface having elasticity can be produced by cutting a plate material made of a metal material or the like into a predetermined shape.
Further, the plate-like body having the second surface having elasticity can be produced by cutting the plate material into a predetermined shape and then press-molding it with a mold. Further, the plate-like body having the second surface having elasticity can also be produced by injection molding a resin material. Further, a plate material using a metal material for the first surface or the third surface and using a resin material for the second surface can be produced by insert molding.

Hereinafter, each member which comprises the lithium ion capacitor which concerns on 1st embodiment of this invention is demonstrated.

As shown in FIG. 1, the positive electrode 10 can include a positive electrode current collector 12 and a positive electrode active material layer 14.

As the positive electrode current collector 12, a porous metal foil can be used. More specifically, as the positive electrode current collector 12, an expanded metal having holes penetrating the front and back surfaces can be used. Thereby, lithium ions can move through the positive electrode current collector 12. Therefore, lithium ions can be pre-doped into the negative electrode 20 through the positive electrode current collector 12.
Examples of the material of the positive electrode current collector 12 include aluminum and stainless steel. The thickness of the positive electrode current collector 62 is not particularly limited, but is, for example, 20 to 50 μm.

The positive electrode active material layer 14 is formed on the positive electrode current collector 12. In the example illustrated in FIG. 1, the positive electrode active material layer 14 is formed on both surfaces of the positive electrode current collector 12, but may be formed only on one surface. Although the thickness of the positive electrode active material layer 14 is not specifically limited, For example, it is 60-90 micrometers, Preferably it is 70-80 micrometers.

For example, the positive electrode active material layer 14 is prepared by dispersing a powdery positive electrode active material, a binder (binder), and a thickener in an aqueous solvent or an organic solvent, and adjusting the slurry. It can form by apply | coating to the surface of this and drying. You may mix a electrically conductive agent as needed.
As a more specific method for forming the positive electrode active material layer 14, first, the positive electrode active material, the conductive agent, and ion-exchanged water are mixed, then the thickener is mixed, and then the binder is mixed. And a method of adjusting the slurry.

The positive electrode active material is a material that can reversibly support anions such as hexafluorophosphate (PF ₆ ⁻ ) and tetrafluoroborate (BF ₄ ⁻ ). The positive electrode active material may be capable of supporting lithium ions, for example. More specifically, examples of the positive electrode active material include activated carbon, polyacene-based material (PAS) that is a heat-treated product of aromatic condensation polymer, and the like.

As the binder (binder), a fluoroacrylic resin can be used. More specifically, a fluoropolymer obtained from a monomer component containing vinylidene fluoride (VDF) and propylene hexafluoride (HFP), an alkyl (meth) acrylate, and a functional group-containing unsaturated group. Examples thereof include a composite polymer with a functional group-containing polymer obtained from a monomer component containing a monomer.

Examples of the thickener include carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), polyethylene glycol (PEG) and the like. These may be used alone or in combination.

As the conductive agent, for example, acetylene black, graphite, metal powder, or the like can be used.

As shown in FIG. 1, the negative electrode 20 can include a negative electrode current collector 22 and a negative electrode active material layer 24.

As the negative electrode current collector 22, a porous metal foil can be used. More specifically, as the negative electrode current collector 22, an expanded metal having holes penetrating the front and back surfaces can be used.
Examples of the material of the negative electrode current collector 22 include copper, stainless steel, nickel, and the like. Although the thickness of the negative electrode collector 22 is not specifically limited, For example, it is 20-50 micrometers.

The negative electrode active material layer 24 is formed on the negative electrode current collector 22. The negative electrode active material layer 24 may be formed on both surfaces of the negative electrode current collector 22, or may be formed only on one surface. Although the thickness of the negative electrode active material layer 24 is not specifically limited, For example, it is 20-30 micrometers.

The negative electrode active material layer 24 is prepared by, for example, dispersing a powdery negative electrode active material, a binder (binder), and a thickener in an aqueous medium or an organic solvent to prepare a slurry, and the slurry is used as the negative electrode current collector 22. It is formed by applying to the surface and drying. You may mix a electrically conductive agent as needed.

The negative electrode active material is a material that can occlude and release lithium ions. More specifically, examples of the negative electrode active material include graphite (graphite), non-graphitizable carbon, and PAS.
As the binder, thickener and conductive agent for forming the negative electrode active material layer 24, for example, the binder, thickener and conductive agent exemplified for forming the positive electrode active material layer 14 are used. it can.

The capacitance per unit mass of the negative electrode active material is at least three times the capacitance per unit mass of the positive electrode active material, and the mass of the positive electrode active material is larger than the mass of the negative electrode active material Is preferred. Thereby, the capacity | capacitance of a lithium ion capacitor can be enlarged more.
In this specification, the electrostatic capacity of the positive electrode or the negative electrode indicates the amount of electricity flowing to the capacitor cell per unit voltage of the positive electrode or the negative electrode, and the unit is F.

As shown in FIG. 1, the lithium electrode 30 can include a lithium electrode current collector 32 and a lithium foil 34.

As the lithium electrode current collector 32, a porous metal foil can be used. The material of the lithium electrode current collector 32 is preferably a material that does not react with lithium ions, and specific examples include copper and stainless steel. The thickness of the lithium electrode current collector 32 is not particularly limited, but is, for example, 10 to 200 μm.

The lithium foil 34 is, for example, pressure bonded to one surface of the lithium electrode current collector 32. The material of the lithium foil 34 is lithium. The lithium foil 34 can function as a lithium ion supply source. That is, by immersing the lithium electrode current collector 32 and the negative electrode current collector 22 in the electrolytic solution while being electrically connected and short-circuited, the lithium foil 34 is dissolved in the electrolytic solution and becomes lithium ions. be able to. Then, lithium ions can be electrochemically pre-doped into the negative electrode active material layer 24 via the electrolytic solution. Although the thickness of the lithium foil 34 is not specifically limited, For example, it is 50-300 micrometers.

The pre-doping may be performed on at least one of the positive electrode active material layer 14 and the negative electrode active material layer 24. However, in consideration of the complexity of the process and the capacity of the lithium ion capacitor, the pre-doping of lithium ions is This is preferably performed only on the negative electrode active material layer 24.

As the separator 40, a porous material that is durable against the electrolytic solution, the positive electrode active material, and the negative electrode active material can be used. More specifically, as the separator 40, for example, a nonwoven fabric made of cellulose, rayon, polyethylene, polypropylene, aramid resin, amideimide, polyphenylene sulfide, polyimide, or the like, or a porous film can be used. Although the thickness of the separator 40 is not specifically limited, For example, it is 20-50 micrometers. The separator 40 can isolate the positive electrode 10, the negative electrode 20, and the lithium electrode 30 from each other. Moreover, the separator 40 can infiltrate electrolyte solution.

As the electrolytic solution, an aprotic organic solvent electrolytic solution containing lithium salt as an electrolyte is used.
Examples of the aprotic organic solvent include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, acetonitrile, dimethoxyethane, tetrahydrofuran, dioxolane, methylene chloride, sulfolane and the like. These solvents may be used alone or in combination of two or more.

Examples of the lithium salt include LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , Li (C ₂ F ₅ SO ₂ ) ₂ N, and the like. The concentration of the lithium salt in the electrolytic solution is, for example, 0.5 to 1.5 mol / l.

Hereinafter, an example of the manufacturing method of the lithium ion capacitor which concerns on 1st embodiment of this invention is shown.

First, a first plate-like body 61A, a second plate-like body 62A, and a frame-like body 63A are prepared. At this time, an electrolyte solution inlet is provided in the frame 63A.
Examples of the method of providing the electrolyte injection port include a method of forming the electrolyte injection port when molding with a mold, or a method of forming an electrolyte injection port by performing drilling after molding. .

Next, the second plate-like body 62A is bonded to the lower surface side of the frame-like body 63A, and the lower opening of the frame-like body 63A is closed to form a bottomed box shape. When the electrode laminated body 50 is accommodated in the bottomed box shape, the electrode laminated body 50 can be placed on the bottom (that is, the second plate-like body 62A).

Moreover, the electrode laminated body 50 formed by laminating | stacking the positive electrode 10, the negative electrode 20, and the separator 40 is prepared.
The positive electrode 10 can be manufactured by first preparing a mixed slurry containing a carbon material, a conductive agent, and a binder, applying the slurry to an aluminum foil that is the positive electrode current collector 12 and drying it.
The negative electrode 20 can be prepared by first preparing a mixed slurry containing a carbon material and a binder, applying the slurry to a copper foil as the negative electrode current collector 22 and drying it.

The lithium electrode 30 can be produced by pressing the lithium foil 34 to stainless steel as the lithium electrode current collector 32.

And after laminating | stacking with the separator 40 interposed between the positive electrode 10 and the negative electrode 20, each positive electrode lead 18 of each positive electrode current collector 12 is ultrasonically welded to the positive electrode terminal 16, and each negative electrode current collector 22 The negative electrode lead 28 is ultrasonically welded to the negative electrode terminal 26.

Next, the electrode laminated body 50 with a terminal is accommodated in the frame-like body 63A to which the second plate-like body 62A is bonded. At this time, the positive electrode terminal 16 and the negative electrode terminal 26 are arranged in the concave portion 73 of the frame-like body 63A and fixed with an adhesive.

Then, the first plate-like body 61A is bonded to the upper surface side of the frame-like body 63A so as to close the upper opening of the frame-like body 63A. As a result, the electrode laminate 50 is completely accommodated in the case 60A.

The electrolytic solution is injected from the electrolytic solution injection port of the frame-like body 63A, and the case 60A is filled with the electrolytic solution. Thereafter, the electrolyte solution inlet is closed by heat sealing or the like, and the case 60A is completely sealed. By holding in this state for a predetermined time, the lithium ion capacitor according to the first embodiment of the present invention can be manufactured.

When the electrolytic solution is injected, all the negative electrode and the lithium foil are in electrochemical contact, and lithium ions eluted from the lithium foil into the electrolytic solution move to the negative electrode over time. Supported. That is, pre-doping of lithium ions proceeds.
In supporting lithium ions on the negative electrode, since the electrode is held by the elastic second surface of the plate-like body, it is possible to prevent the negative electrode from being deformed due to distortion caused by the penetration of lithium ions into the negative electrode.

FIG. 9A is a cross-sectional view schematically showing an example of a lithium ion capacitor before lithium ion pre-doping, and FIG. 9B shows a lithium ion capacitor after completion of lithium ion pre-doping. It is sectional drawing which shows an example typically.
9A and 9B, the positive electrode terminal 16, the negative electrode terminal 26, and the lithium current collector 32 are not shown for convenience of explanation, and the electrode stack 50 is also simplified.

As shown in FIG. 9A, the lithium foil 34 is accommodated in the case before lithium ion pre-doping. On the other hand, as shown in FIG. 9B, when the pre-doping of lithium ions is completed, the lithium foil 34 disappears because it is completely dissolved in the electrolytic solution.
In the lithium ion capacitor according to the first embodiment of the present invention, the third surface of the first plate 61A is formed by the bellows-like elastic portion 71A provided on the second surface of the first plate 61A. Pressure can be applied to the electrodes. Even when the volume of the contents in the cell is reduced by doping lithium ions, the third surface of the plate is pressed by pressing the third surface with the elastic second surface of the plate. It is possible to follow the volume change within. As a result, the distance between the electrodes can be kept narrow, so that the battery volume can be reduced and the reduction in energy capacity can be prevented. Moreover, since the moving distance of lithium ions in the electrolytic solution can be reduced, the charge / discharge capacity can be increased.

Below, it enumerates about the effect of the lithium ion capacitor which concerns on 1st embodiment of this invention.
(1) In the lithium ion capacitor according to the present embodiment, at least one of the upper surface and the bottom surface of the case is positioned on the inner side of the first surface including the outer edge and the first surface, and the second surface having elasticity. It consists of a plate-like body having a surface and a flat plate-like third surface located inside the second surface. Specifically, a bellows-like elastic part is provided on the second surface.
Since the bellows-like elastic portion has elasticity, the second surface having elasticity can be formed on the plate-like body. As described above, when the elastic second surface is provided on the plate-like body, the third surface of the plate-like body can be pressed against the electrode by the elastic action of the second surface of the plate-like body.
Therefore, even if the volume of the contents in the cell is reduced by doping lithium ions, the third surface of the plate is pressed against the electrode by pressing the third surface of the plate to the volume in the cell. Follow changes. As a result, the distance between the electrodes can be kept narrow, so that the battery volume can be reduced and the reduction in energy capacity can be prevented. Moreover, since the moving distance of lithium ions in the electrolytic solution can be reduced, the charge / discharge capacity can be increased.

(2) In the lithium ion capacitor of the present embodiment, the case further includes a box-like body having an upper opening and a lower opening, and further includes a frame-like body surrounding the side surface of the electrode laminate, and the plate-like body An end portion of the first surface is joined to the frame body so as to close the upper opening or the lower opening of the frame body.
When the case includes the frame-like body, the electrode laminate can be firmly pressed by the third surface of the plate-like body while fixing the first surface of the plate-like body to the frame-like body. Moreover, since the frame-like body has a thickness, the electrolyte solution inlet can be easily formed. Therefore, it is easy to inject electrolyte.
Furthermore, the strength of the entire lithium ion capacitor can be improved by providing the case with a frame-like body.

(Second embodiment)
Hereinafter, a second embodiment which is an embodiment of the lithium ion capacitor of the present invention will be described.
In the lithium ion capacitor according to the second embodiment of the present invention, the case does not have a frame-like body. Except for the configuration of the case, the lithium ion capacitor according to the second embodiment of the present invention has the same configuration as the lithium ion capacitor according to the first embodiment of the present invention.
Hereinafter, the detailed description of the configuration common to the first embodiment of the present invention will be omitted, and the configuration of the different case will be mainly described.

FIG. 10 is a perspective view schematically showing an example of a lithium ion capacitor according to the second embodiment of the present invention.
In the lithium ion capacitor 200 shown in FIG. 10, as in the lithium ion capacitor 100 shown in FIG. 1, an electrode laminate formed by laminating a positive electrode, a negative electrode, and a separator is accommodated in the case 160A.

As shown in FIG. 10, the case 160A includes a first plate-like body 161A provided on the top and side surfaces of the case 160A, and a second plate-like body 162A provided on the bottom and side surfaces of the case 160A. ing.
The first plate-like body 161A is provided with an extending portion 172A on the outer side of the upper surface of the case 160A (the first surface of the first plate-like body 161A). The second plate-like body 162A is provided with an extending portion 174A further outside the bottom surface of the case 160A (the first surface of the second plate-like body 162A).
An organic electrolyte (electrolytic solution) containing lithium ions is injected into case 160A.

The positive electrode terminal 16 is provided between the first plate-like body 161A and the second plate-like body 162A, for example. As shown in FIG. 10, the positive terminal 16 extends outward from the outer periphery of the case 160A.

The negative electrode terminal 26 is provided between the first plate-like body 161A and the second plate-like body 162A, for example, apart from the positive electrode terminal 16. As shown in FIG. 10, the negative electrode terminal 26 extends outward from the outer periphery of the case 160A.

In FIG. 10, the positive terminal 16 is provided at the left end (one end) of the case 160A, and the negative terminal 26 is provided at the right end (the other end) of the case 160A. However, the positions of the positive terminal 16 and the negative terminal 26 are not particularly limited.

As shown in FIG. 10, the extended portion 172A of the first plate-like body 161A is joined to the extended portion 174A of the second plate-like body 162A by an adhesive, welding, welding, or the like.

Also in the lithium ion capacitor according to the second embodiment of the present invention, at least one of the upper surface and the bottom surface of the case is located on the inner side of the flat first surface including the outer edge and the first surface, and is elastic. It consists of the plate-shaped body which has the 2nd surface which has this, and the flat 3rd surface located inside the said 2nd surface.

11 is a cross-sectional view schematically showing a case constituting the lithium ion capacitor shown in FIG.
In FIG. 11, a sectional view of only the case is shown, and illustration of other members constituting the lithium ion capacitor is omitted.

A first plate-like body 161A constituting the case 160A shown in FIG. 11 includes a flat plate-like first surface including an outer edge, an elastic second surface located on the inner side of the first surface, and the second And a flat plate-like third surface located inside the surface.
Further, a bellows-like elastic portion 171A is provided on the second surface of the first plate-like body 161A.

Similarly, the second plate-like body 162A constituting the case 160A has a flat plate-like first surface including an outer edge, an elastic second surface located inside the first surface, and the second surface. And a flat plate-like third surface located inside.
Further, a bellows-like elastic portion 173A is provided on the second surface of the second plate-like body 162A.

In the case 160A shown in FIG. 11, the bellows-like elastic portion may not be provided on one of the first plate-like body 161A and the second plate-like body 162A. That is, one of the first plate-like body 161A and the second plate-like body 162A may not have the second surface having elasticity.

FIG. 12 is a perspective view schematically showing another example of the lithium ion capacitor according to the second embodiment of the present invention.
In the lithium ion capacitor 300 shown in FIG. 12, an electrode laminate formed by laminating a positive electrode, a negative electrode, and a separator is housed in the case 260A, similarly to the lithium ion capacitor 100 shown in FIG.

As illustrated in FIG. 12, the case 260A includes a first plate-like body 261A provided on the upper surface and side surfaces of the case 260A, and a second plate-like body 262A provided on the bottom surface of the case 260A. .
The first plate-like body 261A is provided with an extending portion 272A on the outer side of the upper surface of the case 260A (the first surface of the first plate-like body 261A). The second plate-like body 162A has a flat plate shape.
An organic electrolyte (electrolytic solution) containing lithium ions is injected into the case 260A.

The positive electrode terminal (not shown) is provided between the first plate-like body 261A and the second plate-like body 262A, for example. The positive terminal extends outward from the outer periphery of the case 260A.

The negative electrode terminal 26 is provided between the first plate-like body 261A and the second plate-like body 262A, for example, apart from the positive electrode terminal 16. As shown in FIG. 12, the negative electrode terminal 26 extends outward from the outer periphery of the case 260A.

In FIG. 12, the positive terminal is provided at the left end (one end) of the case 260A, and the negative terminal 26 is provided at the right end (the other end) of the case 260A. However, the positions of the positive electrode terminal and the negative electrode terminal 26 are not particularly limited.

As shown in FIG. 12, the extending portion 272A of the first plate-like body 261A is joined to the end portion of the second plate-like body 262A by an adhesive, welding, welding, or the like.

13 is a cross-sectional view schematically showing a case constituting the lithium ion capacitor shown in FIG.

The first plate-like body 261A constituting the case 260A shown in FIG. 13 has a flat plate-like first surface including an outer edge, an elastic second surface located on the inner side of the first surface, and the second And a flat plate-like third surface located inside the surface.
Further, a bellows-like elastic portion 271A is provided on the second surface of the first plate-like body 261A.

In the case 260A shown in FIG. 13, bellows-like elastic portions may be provided on both the first plate-like body 261A and the second plate-like body 262A. That is, both the first plate-like body 261A and the second plate-like body 262A may have a second surface having elasticity.
In the case 260A shown in FIG. 13, the first plate-like body 261A may not be provided with the bellows-like elastic portion, and the second plate-like body 262A may be provided with the bellows-like elastic portion. . That is, the first plate-like body 261A may not have the second surface having elasticity, and the second plate-like body 262A may have the second surface having elasticity.

FIG. 14 is a perspective view schematically showing still another example of the lithium ion capacitor according to the second embodiment of the present invention.
In the lithium ion capacitor 400 shown in FIG. 14, as in the lithium ion capacitor 100 shown in FIG. 1, an electrode laminated body in which a positive electrode, a negative electrode, and a separator are laminated is accommodated in the case 360 </ b> A.

As shown in FIG. 14, the case 360A includes a first plate-like body 361A provided on the upper surface of the case 360A, and a second plate-like body 362A provided on the bottom and side surfaces of the case 360A. .
The first plate-like body 361A has a flat plate shape. The second plate-like body 362A is provided with an extending portion 374A further outside the bottom surface of the case 360A (the first surface of the second plate-like body 362A).
An organic electrolyte (electrolytic solution) containing lithium ions is injected into the case 360A.

The positive electrode terminal 16 is provided between the first plate-like body 361A and the second plate-like body 362A, for example. As shown in FIG. 14, the positive terminal 16 extends outward from the outer periphery of the case 360A.

The negative electrode terminal 26 is provided between the first plate-like body 361A and the second plate-like body 362A, for example, apart from the positive electrode terminal 16. As shown in FIG. 14, the negative electrode terminal 26 extends outward from the outer periphery of the case 360A.

In FIG. 14, the positive terminal 16 is provided at the left end (one end) of the case 360A, and the negative terminal 26 is provided at the right end (the other end) of the case 360A. However, the positions of the positive terminal 16 and the negative terminal 26 are not particularly limited.

As shown in FIG. 14, the end of the first plate-like body 361A is joined to the extending portion 374A of the second plate-like body 362A by an adhesive, welding, welding, or the like.

15 is a cross-sectional view schematically showing a case constituting the lithium ion capacitor shown in FIG.

The first plate-like body 361A constituting the case 360A shown in FIG. 15 includes a flat plate-like first surface including an outer edge, an elastic second surface located on the inner side of the first surface, and the second And a flat plate-like third surface located inside the surface.
Further, a bellows-like elastic portion 371A is provided on the second surface of the first plate-like body 361A.

In the case 360A shown in FIG. 15, bellows-like elastic portions may be provided on both the first plate-like body 361A and the second plate-like body 362A. That is, both the first plate-like body 361A and the second plate-like body 362A may have a second surface having elasticity.
In the case 360A shown in FIG. 15, the first plate-like body 361A is not provided with the bellows-like elastic portion, and the second plate-like body 362A may be provided with the bellows-like elastic portion. . That is, the first plate-like body 361A may not have the second surface having elasticity, and the second plate-like body 362A may have the second surface having elasticity.

In the lithium ion capacitor according to the second embodiment of the present invention, the configuration of the bellows-like elastic portion provided on the plate-like body is the same as the configuration of the bellows-like elastic portion described in the first embodiment of the present invention. .
In the lithium ion capacitor according to the second embodiment of the present invention, when the bellows-like elastic portion is provided on both the first plate-like body and the second plate-like body, the bellows of the first plate-like body. The configuration of the elastic portion and the configuration of the bellows-like elastic portion of the second plate are preferably the same, but may be different from each other.

In the lithium ion capacitor according to the second embodiment of the present invention, as the constituent material of the plate-like body, the constituent material of the plate-like body described in the first embodiment of the present invention can be used.
In particular, it is preferable to use a metal material as a constituent material of the plate-like body.

The method for producing the plate-like body is the same as that in the first embodiment of the present invention. For example, a plate-like body having a predetermined shape can be produced by press molding with a mold.

The lithium ion capacitor according to the second embodiment of the present invention is a lithium ion capacitor according to the first embodiment of the present invention, except that a case is produced using the first plate body and the second plate body. It can be manufactured by the same method as the capacitor.

In 2nd embodiment of this invention, while being able to exhibit the effect (1) demonstrated in 1st embodiment of this invention, the following effects can be exhibited.
(3) In the lithium ion capacitor of this embodiment, the extending part is provided further outside the first surface of the plate-like body. Therefore, a case can be produced without using a frame-like body.

(4) In the lithium ion capacitor of the present embodiment, since the extending portion is provided further outside the first surface, the bent portion formed between the first surface and the extending portion has high rigidity of the plate-like body. Become. Therefore, even if a force is applied to the lithium ion capacitor, it is difficult to apply a local force between the plate-like body and the other plate-like body, and it is difficult to peel off at the joint portion.

(Other embodiments)
In the lithium ion capacitor according to the embodiment of the present invention, the shape of the case is not limited to the rectangular column shape (cuboid shape), and the shape of an arbitrary column such as a cylindrical shape, an elliptical column shape, a long cylindrical shape, or a polygonal column shape. If it is.

In the lithium ion capacitor according to the embodiment of the present invention, the outline of the first surface of the plate-like body constituting the case is not limited to a rectangular shape in plan view, but a circular shape, an elliptical shape, an oval shape, It may be an arbitrary shape such as a polygonal shape.

In the lithium ion capacitor according to the embodiment of the present invention, when the bellows-like elastic portion is provided on the second surface of the plate-like body, the shape of the bellows-like elastic portion is limited to a rectangular shape in plan view. It may be an arbitrary shape such as a circular shape, an elliptical shape, an oval shape, or a polygonal shape.
In any case, the bellows-like elastic portion is preferably provided along the outline of the first surface of the plate-like body.

Further, when the bellows-like elastic portion is viewed in plan, the bellows-like elastic portion does not necessarily have to be continuous, and a part thereof may be interrupted. A plurality of independent bellows-like elastic portions may be provided.
Also in the above case, the surface on which the bellows-like elastic portion is provided can be considered as the second surface.

In the lithium ion capacitor according to the embodiment of the present invention, it is sufficient that the second surface of the plate-shaped body can be expanded and contracted, and a configuration other than that in which the bellows-like elastic portion is provided on the second surface may be employed. .
Further, for example, the first plate-like body may have a configuration in which a bellows-like elastic portion is provided, and the second plate-like body may have a configuration other than that in which a bellows-like elastic portion is provided. .

In the lithium ion capacitor according to the embodiment of the present invention, the first surface and the third surface of the plate-like body may be subjected to processing such as concavities and convexities for improving the strength, as long as it is flat.

In the lithium ion capacitor according to the embodiment of the present invention, the third surface of the plate-like body is closer to the electrode laminate than the first surface of the plate-like body in a cross section perpendicular to the upper surface of the case. Although it is preferable, it may be at the same position as the first surface of the plate-like body, or may be at a position farther from the electrode laminate than the first surface of the plate-like body.

In the lithium ion capacitor according to the embodiment of the present invention, at least one of the upper surface and the bottom surface of the case is located on the flat plate-shaped first surface including the outer edge and the first surface, and has elasticity. It consists of a plate-like body having two surfaces and a flat plate-like third surface located inside the second surface as an essential component.
The essential components include various configurations detailed in the first embodiment, the second embodiment, and other embodiments of the present invention (for example, the shape of the case, the configuration of the second surface of the plate, The desired effect is obtained by appropriately combining the configuration of the bellows-like elastic portion, the presence and configuration of the extending portion, the configuration of the frame-like body, the configuration of the electrode laminate, the positions of the positive and negative electrodes, the position of the lithium electrode, etc. be able to.

DESCRIPTION OF SYMBOLS 10 Positive electrode 20 Negative electrode 30 Lithium electrode 34 Lithium foil 40 Separator 50 Electrode laminated body 60A, 60E, 160A, 260A, 360A Case 61A, 61B, 61C, 61D, 61E, 161A, 261A, 361A body)
62A, 62E, 162A, 262A, 362A Plate (second plate)
61A _1st plate-like body 61A _2nd plate-like body 2nd surface 61A _3rd plate-like body 3rd surface 63A, 63B, 63E Frame-like body 71A, 71B, 71C, 71D, 171A, 173A, 271A, 371A Bellows-like elastic part 72B, 172A, 174A, 272A, 374A Extension part 100, 200, 300, 400 Lithium ion capacitor

Claims (9)

An electrode laminate comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and an electrode stack formed by stacking the positive electrode, the negative electrode, and the separator is contained in a case, and lithium is contained in the case A lithium ion capacitor into which an organic electrolyte containing ions is implanted,
At least one of the upper surface and the bottom surface of the case is a flat plate-shaped first surface including an outer edge, an elastic second surface located on the inner side of the first surface, and an inner surface of the second surface. A lithium ion capacitor comprising a plate-like body having a flat plate-like third surface. The lithium ion capacitor according to claim 1, wherein a bellows-like elastic portion is provided on the second surface. The lithium ion capacitor according to claim 2, wherein the bellows-like elastic portion is provided along an outline of the first surface. The lithium ion capacitor according to claim 1, wherein an extending portion is provided further outside of the first surface. The case further comprises a box-like body having an upper opening and a lower opening and a frame-like body surrounding the side surface of the electrode laminate,
The end of the first surface of the plate-like body is joined to the frame-like body so as to close the upper opening or the lower opening of the frame-like body. The lithium ion capacitor described. The lithium ion capacitor according to claim 5, wherein the frame body has at least an insulating portion. The lithium ion capacitor according to claim 1, wherein the plate-like body is made of metal. The cross section perpendicular to the upper surface of the case, the third surface of the plate-like body is located closer to the electrode laminate than the first surface of the plate-like body. The lithium ion capacitor described. The case used for the lithium ion capacitor in any one of Claims 1-8.

Images