JP2012216653A - Power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new structure of a lithium ion secondary battery or a lithium ion capacitor in which production efficiency can be improved without deteriorating characteristics thereof.SOLUTION: A lithium ion secondary battery or a lithium ion capacitor including a shaft core for winding a positive electrode, a negative electrode, and a separator and a ring-shaped negative electrode current collector member for performing current collection of a negative electrode potential shall include at least one of the negative electrode current collector member having a plurality of holes and a shaft core having a slit.

Description

  The present invention relates to an electricity storage device such as a lithium ion secondary battery or a lithium ion capacitor, and in particular, includes an electrode group in which a positive and negative electrode plate is wound through a separator, and a positive and negative electrode current collecting lead is a positive and negative electrode plate. The present invention relates to an electricity storage device having a structure that is led out from one side and connected to each of positive and negative electrode terminals disposed on opposite sides of an electrode group.

  Conventionally, lithium ion capacitors have been used in various fields. Among them, a cylindrical wound lithium ion capacitor in which a cylindrical battery can accommodates a group of electrodes in which a strip-like positive and negative electrode plate is wound around a shaft in a spiral shape through a separator is a high output power, high voltage, A long service life is possible, and therefore, it is being used in various fields such as a main power source of an automated guided vehicle (AGV), a low voltage guarantee device, and a regenerative auxiliary power source.

  In general, a wound lithium ion secondary battery or a lithium ion capacitor injects an electrolyte from the upper part of the shaft core, and soaks the electrolyte into the wound group. In order to improve productivity, it is required to improve liquid injection properties. If injection is performed without taking countermeasures, it takes 1 hour or more to re-inject. For this reason, Patent Document 1 discloses a measure for soaking the wound group as quickly as possible, such as providing a groove in the electrode plate.

  However, when the electrode plate is processed, there is a possibility that the characteristics such as the lithium ion secondary battery and the lithium ion capacitor are affected, for example, the capacity is reduced.

  If the solution is injected without taking any measures after all, the specified amount of electrolyte cannot be injected once. After the injection, the solution is allowed to stand for about 1 hour and then re-injected, and the specified amount of electrolyte is injected. Although it is common to liquefy, this method has poor production efficiency and is not suitable for mass production.

JP 2009-043718 A

  In view of the above problems, an object of the present invention is to provide a new structure of an electricity storage device such as a lithium ion secondary battery or a lithium ion capacitor that can increase production efficiency without deteriorating characteristics. .

  A positive electrode having a positive electrode lead piece formed in a comb shape on one side along the longitudinal direction and a negative electrode having a negative electrode lead piece formed in a comb shape on one side along the longitudinal direction are arranged around the axis via a separator. And the positive and negative electrode lead pieces are disposed opposite to the electrode group led out on the opposite side and the end face of the wound electrode group, and the tip of the positive electrode lead piece is joined to the outer peripheral surface, A ring-shaped positive current collecting member for collecting electric potential and an end face opposite to the end face on which the positive current collecting member of the wound electrode group is located, and the tip of the negative electrode lead piece are joined to the outer peripheral face. A ring-shaped negative electrode current collecting member that collects the potential of the negative electrode, a bottomed cylindrical battery can that accommodates the electrode group and the positive and negative current collecting members together with an electrolyte, and a battery can is sealed through a gasket Positive current collector disposed between the battery lid and the electrode group and the battery lid And an insulator covering the lead piece joined to the positive electrode current collector member from at least the outer peripheral surface of the material to the upper part of the electrode group, wherein the negative electrode current collector member has a plurality of holes. It is assumed that the electricity storage device has the structure as described above.

  At that time, the negative electrode current collecting member has a substantially circular shape having a bottom part of the central part and a convex part of the peripheral part, and has a plurality of holes in the upper surface of the convex part and the wall part of the convex part. And preferred.

  Further, it is preferable that the negative electrode current collecting member has a substantially circular shape having a bottom portion of the central portion and a convex portion of the peripheral portion, and has a plurality of holes connecting the upper surface of the convex portion and the wall portion of the convex portion. .

  Further, the negative electrode current collecting member has a substantially circular shape having a bottom portion of the central portion and a convex portion of the peripheral portion, and has a plurality of holes on the top surface of the convex portion, and at least one of the plurality of hole portions has a top surface. It is preferable that it is a plurality of holes connecting the wall portion of the convex portion.

  Furthermore, it is preferable that the negative electrode current collecting member has a substantially circular shape having a bottom portion at the central portion and a convex portion at the peripheral portion, and has a plurality of holes on the upper surface of the convex portion.

  Alternatively, a positive electrode having a positive electrode lead piece formed in a comb shape on one side along the longitudinal direction and a negative electrode having a negative electrode lead piece formed in a comb shape on one side along the longitudinal direction are arranged via a separator. The positive and negative electrode lead pieces are wound around the electrode group arranged opposite to each other and the end face of the wound electrode group, and the tip of the positive electrode lead piece is joined to the outer peripheral surface, A ring-shaped positive current collecting member that collects the potential of the positive electrode and an end surface opposite to the end surface on which the positive electrode current collecting member of the wound electrode group is located, and the tip of the negative electrode lead piece is the outer peripheral surface A ring-shaped negative electrode current collecting member that collects the negative electrode potential, a bottomed cylindrical battery can that contains the electrode group and the positive and negative current collecting members together with an electrolyte, and a battery can through a gasket. It is placed between the battery lid to be sealed and the electrode group and battery lid. And an insulator covering a lead piece joined to the positive electrode current collector member from at least the outer peripheral surface of the positive electrode current collector member to the upper part of the electrode group, wherein the shaft core has a slit. It is assumed that the electricity storage device has a structure.

  In that case, it is preferable that the edge part by the side of the negative electrode current collection member of an axial center has a slit.

  Moreover, it is preferable that the side surface portion of the shaft core has a slit.

  Further, a positive electrode having a positive electrode lead piece formed in a comb shape on one side along the longitudinal direction and a negative electrode having a negative electrode lead piece formed in a comb shape on one side along the longitudinal direction are arranged with an axial core through a separator. The positive and negative electrode lead pieces are wound around the electrode group arranged opposite to each other and the end face of the wound electrode group, and the tip of the positive electrode lead piece is joined to the outer peripheral surface, A ring-shaped positive current collecting member that collects the potential of the positive electrode and an end surface opposite to the end surface on which the positive electrode current collecting member of the wound electrode group is located, and the tip of the negative electrode lead piece is the outer peripheral surface A ring-shaped negative electrode current collecting member that collects the negative electrode potential, a bottomed cylindrical battery can that contains the electrode group and the positive and negative current collecting members together with an electrolyte, and a battery can through a gasket. The battery lid to be sealed and the electrode group and the battery lid are arranged And an insulator covering a lead piece bonded to the positive electrode current collector member from at least the outer peripheral surface of the electrode current collector member to the upper part of the electrode group, wherein the negative electrode current collector member has a plurality of holes. And a power storage device having a structure in which the shaft core has a slit.

  At that time, the negative electrode current collecting member has a substantially circular shape having a bottom part of the central part and a convex part of the peripheral part, and has a plurality of holes in the upper surface of the convex part and the wall part of the convex part. And preferred.

  Further, it is preferable that the negative electrode current collecting member has a substantially circular shape having a bottom portion of the central portion and a convex portion of the peripheral portion, and has a plurality of holes connecting the upper surface of the convex portion and the wall portion of the convex portion. .

  Further, the negative electrode current collecting member has a substantially circular shape having a bottom portion of the central portion and a convex portion of the peripheral portion, and has a plurality of holes on the top surface of the convex portion, and at least one of the plurality of hole portions has a top surface. It is preferable that it is a plurality of holes connecting the wall portion of the convex portion.

  Furthermore, it is preferable that the negative electrode current collecting member has a substantially circular shape having a bottom portion at the central portion and a convex portion at the peripheral portion, and has a plurality of holes on the upper surface of the convex portion.

  In addition, it is preferable that the end portion of the shaft core on the negative electrode current collecting member side has a slit.

  Furthermore, it is preferable that the side surface portion of the shaft core has a slit.

  According to the present invention, in the past, it was left for about 1 hour after the injection, and then the injection was performed again. Even though the specified amount of electrolyte was put, it was re-injected only by leaving it for about 30 minutes after the injection. The liquid could be dispensed and the injection time could be shortened.

It is sectional drawing of the lithium ion capacitor which shows an example of embodiment which can apply this invention. It is the top view and sectional drawing of a negative electrode current collection ring which has a horizontal hole in the internal peripheral surface of embodiment which can apply this invention. It is the top view and sectional drawing of a negative electrode current collection ring which has a horizontal hole in the internal peripheral surface of embodiment which can apply this invention. It is the top view and sectional drawing of a negative electrode current collection ring which has a horizontal hole in the internal peripheral surface of embodiment which can apply this invention. It is the top view and sectional drawing of a negative electrode current collection ring which has a horizontal hole in the internal peripheral surface of embodiment which can apply this invention. It is the perspective view and sectional drawing of the shaft core of embodiment which can apply this invention. It is the perspective view and sectional drawing of the shaft core of embodiment which can apply this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

<Overall configuration>
As an example of an embodiment for carrying out the invention, a lithium ion capacitor 30 (hereinafter referred to as a capacitor) according to this embodiment as shown in FIG. 1 is provided on a cylindrical steel battery can 8 and a cylindrical upper lid 12 as containers. The wound group 7 and the electrolytic solution are accommodated. A hollow cylindrical shaft core 1 made of polyphenylene sulfide is used at the center of the wound group 7. In the capacitor 30, the battery can 8 has a negative polarity, and the upper lid 12 has a positive polarity. The side periphery of the battery can 8 excluding the bottom surface is covered with a shrink tube (not shown).

  Below the winding group 7, a copper negative electrode current collecting ring 5 for collecting the electric potential from the negative electrode plate is disposed. The outer peripheral surface of the lower end portion of the shaft core 1 is fixed to the inner peripheral surface of the negative electrode current collecting ring 5. The end of the negative electrode lead piece 3 led out from the negative electrode plate is joined to the outer peripheral edge of the negative electrode current collecting ring 5 by welding. The lower part of the negative electrode current collection ring 5 is joined to the inner bottom part of the capacitor container that also serves as the negative electrode external terminal by resistance welding.

  On the other hand, on the upper side of the winding group 7, an aluminum positive electrode current collecting ring 6 for collecting the electric potential from the positive electrode plate is disposed on an almost extension line of the shaft core 1. The positive electrode current collecting ring 6 is fixed to the upper end portion of the shaft core 1. The edge of the positive electrode lead piece 2 led out from the positive electrode plate is joined by welding to the periphery of the flange that integrally extends from the periphery of the positive electrode current collecting ring 6. Above the positive electrode current collecting ring 6, an upper lid 12 that also serves as a positive electrode external terminal is disposed. The upper lid 12 is composed of an upper lid case 12a and an upper lid cap 12b, and is assembled by laminating them and caulking and fixing the periphery of the upper lid case 12a. One side of two positive electrode lead plates 10 in which ribbon-shaped aluminum foils are laminated is joined to the upper surface of the positive electrode current collecting ring 6 by welding. Another side of the positive electrode lead plate 10 is joined to the lower surface of the upper lid case 12 constituting the upper lid 12. The other ends of the two positive electrode lead plates 10 are joined by welding.

  The upper lid 12 is caulked and fixed to the upper part of the capacitor container via an insulating and heat resistant EPDM resin packing 13. For this reason, the inside of the lithium ion capacitor 30 is sealed. In addition, a water-soluble electrolytic solution (not shown) that can infiltrate the entire wound group is injected into the capacitor container. As the electrolytic solution, a solution obtained by dissolving lithium hexafluorophosphate (LiPF6) as a lithium salt in a propylene carbonate solvent is used.

  In the winding group 7, the positive electrode plate and the negative electrode plate are wound around the shaft core 1 through a separator 4 having a thickness of 50 μm and allowing lithium ions to pass therethrough so that the two electrode plates do not directly contact each other. Yes. The positive electrode lead piece 2 and the negative electrode lead piece 3 are respectively disposed on opposite end surfaces of the winding group 7.

  The positive electrode plate constituting the winding group 7 has an aluminum foil porous body as a positive electrode current collector, and the negative electrode plate has an electrolytic copper foil porous body as a negative electrode current collector. In this example, the thicknesses of the aluminum foil and the electrolytic copper foil are set to 20 μm and 15 μm, respectively. Uncoated portions of the positive electrode mixture and the negative electrode mixture are formed on the side edges on one side in the longitudinal direction of the aluminum foil and the electrolytic copper foil, respectively. The uncoated part is cut out in a comb shape, and the positive electrode lead piece 2 and the negative electrode lead piece 3 are formed in the remaining part of the cutout.

<Positive electrode>
As for the positive electrode plate, activated carbon is apply | coated to both surfaces of the aluminum foil W1, and the positive mix layer W2 is formed. Activated carbon is applied substantially uniformly and substantially uniformly on both surfaces of the aluminum foil W1, and dried to form the positive electrode mixture layer W2. After drying, the positive electrode plate is pressed and cut so as to have a positive electrode active material application portion thickness of 65 μm that does not include the aluminum foil W1.

<Negative electrode>
On the other hand, an amorphous carbon material (amorphous carbon material) is used for the negative electrode plate. In the negative electrode plate, the negative electrode mixture layer W4 containing an amorphous carbon material is applied substantially uniformly and substantially uniformly on both surfaces of the electrolytic copper foil W3, and the negative electrode mixture layer W4 is formed. After drying, the negative electrode plate is pressed and cut so as to have a negative electrode active material application portion thickness of 40 μm that does not include the electrolytic copper foil W3.

<Electrolyte>
In this embodiment, although what dissolved lithium hexafluorophosphate in the propylene carbonate solvent which is a water-soluble electrolyte solution was illustrated, this invention is not limited to this. As the water-soluble electrolyte, an electrolyte usually used for a lithium ion capacitor can be used.
(Action etc.)
Furthermore, in the present embodiment, the cylindrical lithium ion capacitor 30 is illustrated, but the present invention is not limited to the shape of the capacitor, and can be applied to, for example, a polygonal capacitor. In addition, the structure of the capacitor to which the present invention is applicable may be other than a battery having a structure in which the upper lid 12 is caulked and fixed to the battery can 8 described above. As an example of such a structure, a capacitor in which the positive and negative external terminals pass through the battery lid and the positive and negative external terminals are pressed against each other through the shaft core 1 in the capacitor 30 container can be cited. Furthermore, it can be applied to a multilayer capacitor instead of a wound capacitor in which positive and negative electrode plates are wound. Of course, the present invention is not limited to capacitor capacity, size, or the like.

Next, an example of the lithium ion capacitor 30 manufactured according to the present embodiment will be described. A comparative example prepared for comparison is also shown.
Example 1
As shown in FIG. 1, the negative electrode current collector ring 5 has a horizontal hole in the inner peripheral surface of the negative electrode current collector ring 5 in order to improve the liquid injection property. A capacitor 30 was manufactured using the negative electrode current collecting ring 5. The negative electrode current collector ring 5 shown in FIG. 1 has a disadvantage that pressing cannot be performed by one molding and a cutting process is performed. For manufacturing the capacitor 30, the shaft core 1 as shown in FIG. 6 was used. The fitting property between the shaft core 1 and the negative electrode current collecting ring 5 was good.

  Moreover, an effect can be expected if the ratio of the hole area on the inner peripheral surface of the negative electrode current collecting ring 5 is 20% or more in terms of the area ratio to the entire inner peripheral surface. On the other hand, when the area ratio exceeds 40%, the strength of the negative electrode current collecting ring 5 starts to decrease, which is not desirable. Therefore, the hole area of the inner peripheral surface of the negative electrode current collecting ring 5 is preferably 20% or more and 40% or less in terms of the area ratio with the entire inner peripheral surface.

In the present embodiment, the ratio of the hole area on the inner peripheral surface of the negative electrode current collecting ring 5 is slightly over 20%.
(Example 2)
As shown in FIG. 4, the negative electrode current collector ring 5 has a horizontal hole on the inner peripheral surface of the negative electrode current collector ring 5, and is open on the surface where the wound group 7 and the negative electrode current collector ring 5 are in contact with each other. It is connected to the hole. By doing so, the area ratio of the hole area of the inner peripheral surface to the front surface of the inner peripheral surface is about 40%, which can be increased by about 20% compared to the first embodiment. Moreover, since the excess thickness can be escaped because the hole becomes large, there is an advantage that it can be manufactured by one press. A capacitor 30 was manufactured using the negative electrode current collecting ring 5. The fitting property between the shaft core 1 and the negative electrode current collecting ring 5 was good.
(Example 3)
As shown in FIG. 5, the inner circumferential surface of the negative electrode current collector ring 5 has a structure in which a horizontal hole is opened, and a hole opened in a surface where the winding group 7 and the negative electrode current collector ring 5 are in contact with each other. It is connected alternately. The area ratio of the lateral holes on the inner peripheral surface is the same as in Example 2 and is about 40%. By doing so, the area ratio of the lateral holes on the inner peripheral surface can be increased by about 20% compared to the first embodiment. Further, since the area ratio of the lateral holes on the inner peripheral surface is increased, an extra thickness can be released, so that there is an advantage that it can be manufactured by one press. A capacitor 30 was manufactured using the negative electrode current collecting ring 5. As shown in FIG. 6, the fitting property between the shaft core 1 and the negative electrode current collecting ring 5 was good.
Example 4
As shown in FIG. 6, a capacitor 30 was manufactured using a structure in which a lateral hole was not formed on the inner peripheral surface of the negative electrode current collecting ring 5. A shaft core having a slit as shown in FIG. 7 was used as the shaft core 1. The fitting property between the shaft core 1 and the current collecting ring 5 was good.
(Comparative example)
As shown in FIG. 6, the inner circumferential surface of the negative electrode current collecting ring 5 has a structure in which there is no horizontal hole. A capacitor 30 was manufactured using the negative electrode current collecting ring 5. The fitting property between the shaft core 1 and the negative electrode current collecting ring 5 was good.

  As shown in Table 1, in the case of Example 1 to Example 3 in which the negative electrode current collector ring 5 having a horizontal hole was used, compared to the case where the negative electrode current collector ring 5 shown in the comparative example was not opened, It takes less time to inject liquid. This is because the area ratio of the inner peripheral surface of the negative electrode current collecting ring 5 to the entire inner peripheral surface of the horizontal hole was an appropriate value.

  Further, as shown in Table 1, when Example 4 is compared with the comparative example, the time required for re-injection in Example 4 is shorter than that in the comparative example. This is because, in Example 4, the negative electrode current collector ring 5 has no horizontal hole, but the shaft core 1 has a slit, and this slit is comparable to the horizontal hole provided in the negative electrode current collector ring 5. It is because it has the effect to do.

  That is, in order to shorten the time required for re-injection of the electrolytic solution, it can be achieved by either providing a horizontal hole on the inner peripheral surface of the negative electrode current collecting ring 5 or by inserting a slit in the shaft core 1. . Of course, it goes without saying that both may be adopted.

  When the initial characteristics of the lithium ion capacitor 30 used in this experiment were measured, no difference was observed depending on the presence or absence of the lateral hole of the negative electrode current collecting ring 5. As a result, it has been found that the present invention can increase the production efficiency without affecting the characteristics.

  Since the present invention provides a method for increasing the production process in manufacturing an electricity storage device such as a lithium ion secondary battery or a lithium ion capacitor, it contributes to the manufacture and sale of the electricity storage device. With the availability of

  DESCRIPTION OF SYMBOLS 1 ... Shaft core, 2 ... Positive electrode lead piece, 3 ... Negative electrode lead piece, 4 ... Separator, 5 ... Negative electrode current collection ring, 6 ... Positive electrode current collection ring, 7 ... Winding group, 8 ... Battery can, 10 ... Positive electrode lead Plate 11: Insulating material 12 ... Upper lid 12a ... Upper lid case 12b ... Upper lid cap 13 ... Packing 30 ... Lithium ion capacitor W1 ... First metal foil W2 ... Positive electrode mixture layer W3 ... Second Metal foil, W4 ... negative electrode composite material layer.

Claims (15)

A positive electrode having a positive electrode lead piece formed in a comb shape on one side along the longitudinal direction and a negative electrode having a negative electrode lead piece formed in a comb shape on one side along the longitudinal direction are arranged around the axis via a separator. A group of electrodes which are wound around and the positive and negative electrode lead pieces are led to opposite sides;
A ring-shaped positive electrode current collecting member that is disposed opposite to the end face of the wound electrode group, the tip end portion of the positive electrode lead piece is joined to the outer peripheral surface, and collects the potential of the positive electrode;
A ring for collecting the potential of the negative electrode, being disposed opposite to the end surface opposite to the end surface on which the positive electrode current collecting member of the wound electrode group is located, and the tip end portion of the negative electrode lead piece being joined to the outer peripheral surface A negative electrode current collector,
A bottomed cylindrical battery can containing the electrode group and the positive and negative current collecting members together with an electrolyte; and
A battery lid for sealing the battery can via a gasket;
An insulator covering a lead piece joined to the positive electrode current collector member over at least an outer peripheral surface of the positive electrode current collector member disposed between the electrode group and the battery lid, and an upper part of the electrode group;
An electricity storage device comprising:
The electricity storage device, wherein the negative electrode current collecting member has a plurality of holes.   The negative electrode current collecting member has a substantially circular shape having a bottom portion at a central portion and a convex portion at a peripheral portion, and has a plurality of holes in an upper surface of the convex portion and a wall portion of the convex portion. The power storage device according to claim 1.   The negative electrode current collecting member has a substantially circular shape having a bottom part of a central part and a convex part of a peripheral part, and has a plurality of holes connecting the upper surface of the convex part and the wall part of the convex part. The power storage device according to claim 1.   The negative electrode current collecting member has a substantially circular shape having a bottom portion of a central portion and a convex portion of a peripheral portion, and has a plurality of hole portions on an upper surface of the convex portion, and at least one of the plurality of hole portions is The electrical storage device according to claim 1, wherein the electrical storage device is a plurality of holes connecting the upper surface and the wall of the convex portion.   The negative electrode current collecting member has a substantially circular shape having a bottom portion at a central portion and a convex portion at a peripheral portion, and has a plurality of holes on an upper surface of the convex portion. The electricity storage device described. A positive electrode having a positive electrode lead piece formed in a comb shape on one side along the longitudinal direction and a negative electrode having a negative electrode lead piece formed in a comb shape on one side along the longitudinal direction are arranged around the axis via a separator. A group of electrodes which are wound around and the positive and negative electrode lead pieces are led to opposite sides;
A ring-shaped positive electrode current collecting member that is disposed opposite to the end face of the wound electrode group, the tip end portion of the positive electrode lead piece is joined to the outer peripheral surface, and collects the potential of the positive electrode;
A ring for collecting the potential of the negative electrode, being disposed opposite to the end surface opposite to the end surface on which the positive electrode current collecting member of the wound electrode group is located, and the tip end portion of the negative electrode lead piece being joined to the outer peripheral surface A negative electrode current collector,
A bottomed cylindrical battery can containing the electrode group and the positive and negative current collecting members together with an electrolyte; and
A battery lid for sealing the battery can via a gasket;
An insulator covering a lead piece joined to the positive electrode current collector member over at least an outer peripheral surface of the positive electrode current collector member disposed between the electrode group and the battery lid, and an upper part of the electrode group;
An electricity storage device comprising:
The power storage device, wherein the shaft core has a slit.   The power storage device according to claim 6, wherein an end of the shaft core on the negative electrode current collecting member side has a slit.   The power storage device according to claim 6 or 7, wherein a side surface portion of the shaft core has a slit. A positive electrode having a positive electrode lead piece formed in a comb shape on one side along the longitudinal direction and a negative electrode having a negative electrode lead piece formed in a comb shape on one side along the longitudinal direction are arranged around the axis via a separator. A group of electrodes which are wound around and the positive and negative electrode lead pieces are led to opposite sides;
A ring-shaped positive electrode current collecting member that is disposed opposite to the end face of the wound electrode group, the tip end portion of the positive electrode lead piece is joined to the outer peripheral surface, and collects the potential of the positive electrode;
A ring for collecting the potential of the negative electrode, being disposed opposite to the end surface opposite to the end surface on which the positive electrode current collecting member of the wound electrode group is located, and the tip end portion of the negative electrode lead piece being joined to the outer peripheral surface A negative electrode current collector,
A bottomed cylindrical battery can containing the electrode group and the positive and negative current collecting members together with an electrolyte; and
A battery lid for sealing the battery can via a gasket;
An insulator covering a lead piece joined to the positive electrode current collector member over at least an outer peripheral surface of the positive electrode current collector member disposed between the electrode group and the battery lid, and an upper part of the electrode group;
An electricity storage device comprising:
The negative electrode current collecting member has a plurality of holes, and the shaft core has a slit.   The negative electrode current collecting member has a substantially circular shape having a bottom portion at a central portion and a convex portion at a peripheral portion, and has a plurality of holes in an upper surface of the convex portion and a wall portion of the convex portion. The electricity storage device according to claim 9.   The negative electrode current collecting member has a substantially circular shape having a bottom part of a central part and a convex part of a peripheral part, and has a plurality of holes connecting the upper surface of the convex part and the wall part of the convex part. The electricity storage device according to claim 9.   The negative electrode current collecting member has a substantially circular shape having a bottom portion of a central portion and a convex portion of a peripheral portion, and has a plurality of hole portions on an upper surface of the convex portion, and at least one of the plurality of hole portions is The electrical storage device according to claim 9, wherein the electrical storage device is a plurality of holes connecting the upper surface and the wall portion of the convex portion.   The negative electrode current collecting member has a substantially circular shape having a bottom portion at a central portion and a convex portion at a peripheral portion, and has a plurality of holes on an upper surface of the convex portion. The electricity storage device described.   The power storage device according to claim 9, wherein an end of the shaft core on the negative electrode current collecting member side has a slit.   The power storage device according to claim 9 or 14, wherein a side surface portion of the shaft core has a slit.

Images