JP2022079183A - Power storage module and manufacturing method for the same - Google Patents

Abstract

To provide a power storage module with a stable shape and a manufacturing method for the same.SOLUTION: The power storage module includes a plurality of stacked power storage cells, end plates provided at both ends in the stacking direction of the plurality of stacked power storage cells, and a restraining member in contact with the end plates from the stacking direction. At the contact surfaces of the end plates and the restraining member, a plurality of projections is provided protruding from one of the end plates and the restraining member toward the other. The plurality of protrusions is aligned in a direction perpendicular to the stacking direction.SELECTED DRAWING: Figure 6

Description

The present technology relates to a power storage module and a method for manufacturing the same.

When a plurality of storage cells are stacked to form a storage module, it is necessary to restrain the plurality of storage cells in the stacking direction. The conventional restraining member is disclosed in International Publication No. 2019/130936 (Patent Document 1) and the like.

International Publication No. 2019/130936

When the storage cell is constrained by the restraining member, the posture of the end plate may fluctuate due to slight variation in the shape of the contact surface thereof, and as a result, the shape of the storage module may not be stable. The conventional structure is not always sufficient in terms of stabilizing the shape of the power storage module.

An object of the present technology is to provide a power storage module having a stable shape and a method for manufacturing the same.

The power storage module according to the present technology includes a plurality of stacked storage cells, end plates provided at both ends of the stacked body of the plurality of storage cells in the stacking direction, and a restraining member that abuts on the end plates from the stacking direction. .. On the contact surface between the end plate and the restraining member, a plurality of protrusions projecting from one of the end plate and the restraining member toward the other are provided, and the plurality of protrusions are arranged in a direction orthogonal to the stacking direction.

The method for manufacturing a power storage module according to the present technology includes a step of stacking a plurality of power storage cells, a step of arranging end plates at both ends of a stack of a plurality of power storage cells in the stacking direction, and fixing a restraint member to the end plate. A step of restraining a laminated body of a plurality of storage cells in the stacking direction is provided. In the process of restraining the laminated body in the stacking direction, the end plate and the restraining member are first brought into contact with each other at a contact point predetermined by the shape of the contact surface between the end plates and the restraining member located at both ends in the stacking direction. ..

According to this technique, it is possible to provide a power storage module having a stable shape and a method for manufacturing the same.

It is a figure which shows the basic structure of an assembled battery. It is a figure which shows the battery cell and the end plate in the assembled battery shown in FIG. It is a figure which shows the battery cell in the assembled battery shown in FIG. It is a figure which shows an example of the structure of the attachment part of the restraint member to the end plate in the assembled battery shown in FIG. It is a figure which shows the state which looked at the structure around the contact part of the restraint member from the outer surface side. It is a figure which shows the state which looked at the structure around the contact part of the restraint member from the inner surface side. It is a schematic diagram which shows the contact portion between the restraint member and an end plate which concerns on a comparative example. It is a schematic diagram which shows the contact portion between the restraint member and an end plate which concerns on one Embodiment. It is a figure which shows the modification of the structure of the attachment part of the restraint member to an end plate. It is a figure which shows one modification of the protrusion. It is a figure which shows the other deformation example of a protrusion.

Hereinafter, embodiments of the present technology will be described. In some cases, the same or corresponding parts are designated by the same reference numeral and the description thereof may not be repeated.

In the embodiments described below, when the number, quantity, etc. are referred to, the scope of the present technique is not necessarily limited to the number, quantity, etc., unless otherwise specified. Further, in the following embodiments, each component is not necessarily essential for the present technique unless otherwise specified.

In addition, in this specification, the description of "comprise", "include", and "have" is in an open-ended format. That is, it includes a certain configuration, but does not exclude the inclusion of other configurations other than the configuration.

FIG. 1 is a diagram showing a basic configuration of the assembled battery 1. FIG. 2 is a diagram showing a battery cell 100 and an end plate 200 included in the assembled battery 1. FIG. 3 is a diagram showing a battery cell 100 in the assembled battery 1.

As shown in FIGS. 1 and 2, the assembled battery 1 as an example of the “storage module” includes a battery cell 100, an end plate 200, and a restraining member 300.

As an example, the battery cell 100 is a lithium ion battery, but the battery cell 100 may be another battery such as a nickel hydrogen battery. Further, in the present disclosure, the "storage module" is not limited to the assembled battery 1, and a capacitor may be used as the "storage cell" instead of the battery cell 100.

The plurality of battery cells 100 are provided so as to be arranged in the Y-axis direction (arrangement direction). The battery cell 100 includes an electrode terminal 110. A separator (not shown) is interposed between the plurality of battery cells 100. A plurality of battery cells 100 sandwiched between the two end plates 200 are pressed by the end plates 200 and constrained between the two end plates 200.

The end plates 200 are arranged at both ends of the assembled battery 1 in the Y-axis direction (arrangement direction). The end plate 200 is fixed to a base such as a case for accommodating the assembled battery 1. Step portions 210 are formed at both ends of the end plate 200 in the X-axis direction.

The restraint member 300 connects the two end plates 200 to each other. The restraint member 300 is attached to a step portion 210 formed on each of the two end plates 200.

By engaging the restraining member 300 with the stepped portion 210 in a state where the compressive force in the Y-axis direction is applied to the laminated body of the plurality of battery cells 100 and the end plate 200, and then releasing the compressive force, 2 A tensile force acts on the restraining member 300 connecting the two end plates 200. As a reaction, the restraint member 300 presses the two end plates 200 in a direction to bring them closer to each other.

The restraint member 300 includes a first member 310 and a second member 320. The first member 310 and the second member 320 are joined to each other by butt welding.

As shown in FIG. 3, the battery cell 100 is formed in a flat rectangular parallelepiped shape. The electrode terminal 110 includes a positive electrode terminal 111 and a negative electrode terminal 112. The electrode terminal 110 is formed on the square housing 120. The housing 120 contains an electrode body and an electrolytic solution (not shown).

FIG. 4 (IV-IV cross-sectional view in FIG. 6) is a diagram showing an example of the structure of the attachment portion of the restraint member 300 to the end plate 200 in the assembled battery 1.

As shown in FIG. 4, the end face of the first member 310 and the end face of the second member 320 face each other. The second member 320 joined to the first member 310 by butt welding includes a first portion 321 and a second portion 322 located on the end side in the stacking direction with respect to the first portion 321.

The plate-shaped second member 320 is bent in the opposite direction along the stacking direction (Y-axis direction) of the battery cells 100. A contact portion 323 is formed between the first portion 321 and the second portion 322 of the second member 320. The contact portion 323 abuts on the end plate 200 from the stacking direction (Y-axis direction). As a result, the second member 320 receives a load (reaction force of the binding force) from the stepped portion 210 of the end plate 200 along the stacking direction (Y-axis direction).

The hole 320A1 and the hole 320A2 are formed in the second member 320. The hole 320A1 is formed to have a larger diameter than the hole 320A2. The hole portion 320A1 and the hole portion 320A2 are formed at positions that are substantially concentric with each other in a state where the second member 320 is bent as shown in FIG. The holes 320A and 320A are combined to form the holes 320A.

The fixing member 400 (bolt) penetrates the holes 320A1 and 320A2 and fixes the second member 320 to the end plate 200. The head of the bolt is housed in the hole 320A1.

The first member 310 located on the center side in the stacking direction is formed thinner than the second member 320 located on the end side in the stacking direction. A spacer 500 is provided between the first member 310 and the battery cell 100.

Next, the structure around the contact portion 323 of the restraint member 300 will be described with reference to FIGS. 5 and 6.

As shown in FIGS. 5 and 6, the first member 310 of the restraint member 300 has a flange portion 311 that wraps around the upper surface and the bottom surface of the battery cell 100 from the side surface of the battery cell 100. By providing the flange portion 311, the rigidity of the first member 310 formed relatively thin can be ensured. The bent and stacked second member 320 is fixed by a plurality of spot welded portions 320B (four in the examples of FIGS. 5 and 6) arranged in the vertical direction.

As shown in FIG. 6, on the contact surface between the end plate 200 and the restraint member 300, two protrusions 323A protruding from the restraint member 300 toward the end plate 200 are provided. The two protrusions 323A are formed so as to line up in the height direction (Z-axis direction) of the battery cell 100 orthogonal to the stacking direction (Y-axis direction) of the battery cell 100. The tip of the protrusion 323A becomes a contact portion 323 that abuts on the end plate 200.

The number of protrusions 323A is not limited to two, and three or more protrusions 323A may be formed. Further, the protrusion may be provided on the end plate 200 side instead of the restraint member 300.

The protrusion 323A shown in FIG. 6 is formed by, for example, pressing a second member 320 made of a plate-shaped member, but the method for forming the protrusion 323A is not limited to this.

The two protrusions 323A may have the same shape or different shapes from each other. The protrusion heights of the two protrusions 323A in the Y-axis direction may be the same as each other or may be different from each other. When the protrusion heights of the two protrusions 323A are different, the protrusion height of the protrusion 323A located on the electrode terminal 110 side may be higher than the protrusion height of the other protrusion 323A, and vice versa.

The protrusion 323A preferably has a shape including an apex when the restraining force of the restraining member 300 is released. In the step of restraining the battery cell 100 and the end plate 200, the above-mentioned apex becomes the point where the end plate 200 first abuts.

The end plate 200 is made of, for example, aluminum, and the restraining member 300 is made of, for example, iron. The restraint member 300 provided with the protrusion 323A is preferably stiffer than the other end plate 200.

FIG. 7 is a schematic view showing a contact portion between the restraint member 300 and the end plate 200 according to the comparative example, and FIG. 8 shows the contact portion between the restraint member 300 and the end plate 200 according to the present embodiment. It is a schematic diagram which shows.

As shown in FIG. 7, in the assembled battery according to the comparative example, the tip surface of the restraint member 300 (second member 320) is designed to abut on the stepped portion 210 of the end plate 200. However, in reality, there are irregularities or inclinations on the contact surfaces of the restraint member 300 and the end plate 200, and there are individual differences (variations) in the irregularities or inclinations. As a result, in the process of fixing the restraining member 300 to the end plate 200 and restraining the laminated body of the plurality of battery cells 100 in the Y-axis direction, the position of the contact portion 323α (point receiving the load) that first abuts is stabilized. However, the direction of the end plate 200 becomes unstable, and the shape of the entire assembled battery 1 (storage module) is difficult to determine. Therefore, the amount of deformation of the sealing portion 130 in the battery cell 100 is also difficult to stabilize.

On the other hand, as shown in FIG. 8, in the assembled battery according to the present embodiment, two protrusions 323A protruding from the restraint member 300 toward the end plate 200 are provided, and the tip of the protrusion 323A is provided. Is the contact portion 323. Therefore, in the step of fixing the restraint member 300 to the end plate 200 and restraining the laminated body of the plurality of battery cells 100 in the Y-axis direction, the contact portion 323 that first abuts (the point where the load is received). Since the position of the battery 1 is stable and the direction of the end plate 200 is stable, the shape of the entire assembled battery 1 (storage module) can be easily determined. Therefore, the amount of deformation of the sealing portion 130 in the battery cell 100 is also stable.

As described above, in the present embodiment, in the step of restraining the laminated body of the plurality of battery cells 100 in the Y-axis direction, the contact points (predetermined by the shape of the contact surface between the end plate 200 and the restraint member 300) ( In the contact portion 323), the end plate 200 and the restraining member 300 are first brought into contact with each other. As a result, the assembled battery 1 having a stable shape can be obtained.

Further, by making the protrusion height of the protrusion 323A located on the electrode terminal 110 side relatively high, the end plate 200 can be intentionally tilted so as to strongly restrain the electrode terminal 110 side, and the battery cell 100 can be tilted. The displacement on the sealing body side can be made relatively small.

FIG. 9 is a diagram showing a modified example of the structure of the attachment portion of the restraint member 300 to the end plate 200. In the examples of FIGS. 4 to 6, the structure in which the plate-shaped second member 320 is bent in the opposite direction along the stacking direction of the plurality of battery cells 100 to form the contact portion 323 has been described, but the second member 320 has been described. It is not always necessary in this disclosure to bend.

As in the modified example of FIG. 9, the first member 310 may extend to the end surface of the end plate 200, and the second member 320 may be provided inside the first member 310. Also in this case, the protrusion 323A and the contact portion 323 are formed on the second member 320.

10 and 11 are views showing a modified example of the protrusion 323A. As shown in FIG. 10, the protrusion 323A may have a regular triangular cross section, and as shown in FIG. 11, the protrusion 323A has a curved contour but a pointed shape. You may.

Although the embodiments of the present technology have been described above, it should be considered that the embodiments disclosed this time are exemplary in all respects and are not restrictive. The scope of the present invention is indicated by the scope of claims and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 set battery, 100 battery cell, 110 electrode terminal, 111 positive electrode terminal, 112 negative electrode terminal, 120 housing, 130 seal, 200 end plate, 210 step, 300 restraint, 310 1st member, 311 flange, 320 2nd member, 320A, 320A1, 320A2 hole part, 320B spot welded part, 321 1st part, 322 2nd part, 323, 323α contact part, 323A protrusion, 400 fixing member, 500 spacer.

Claims (16)

With multiple stacked storage cells
End plates provided at both ends of the laminated body of the plurality of storage cells in the stacking direction, and
The end plate is provided with a restraining member that comes into contact with the end plate from the stacking direction.
On the contact surface between the end plate and the restraint member, a plurality of protrusions protruding from one of the end plate and the restraint member toward the other are provided.
A power storage module in which the plurality of protrusions are arranged in a direction orthogonal to the stacking direction. The power storage module according to claim 1, wherein the plurality of protrusions are provided on the restraining member. The power storage module according to claim 2, wherein the restraining member is a plate-shaped member, and the plurality of protrusions are formed by press punching. Each of the plurality of storage cells includes an external terminal located at the upper end in the height direction orthogonal to the stacking direction.
The power storage module according to any one of claims 1 to 3, wherein two protrusions are provided so as to line up the plurality of power storage cells in the height direction. The power storage module according to claim 4, wherein the protrusion heights of the two protrusions are different from each other. The power storage module according to claim 5, wherein one of the two protrusions located on the external terminal side has a higher protrusion height than the other protrusion. The power storage module according to any one of claims 1 to 6, wherein the plurality of protrusions have a shape including vertices when the restraining force of the restraining member is released. The storage capacity according to any one of claims 1 to 7, wherein one of the end plate and the restraint member provided with the plurality of protrusions is harder than the other of the end plate and the restraint member. module. The process of stacking multiple storage cells and
The step of arranging the end plates at both ends of the laminated body of the plurality of storage cells in the stacking direction, and
A step of fixing a restraining member to the end plate and restraining the laminated body of the plurality of storage cells in the stacking direction is provided.
In the step of restraining the laminated body in the stacking direction, the end plate and the restraining member are at contact points predetermined by the shape of the contact surface between the end plate and the restraining member located at both ends in the stacking direction. A method of manufacturing a power storage module that first contacts and. The method for manufacturing a power storage module according to claim 9, further comprising a step of providing a plurality of protrusions on the restraint member. The method for manufacturing a power storage module according to claim 10, wherein the plate-shaped member is subjected to a press punching step to form the plurality of protrusions. Each of the plurality of storage cells includes an external terminal located at the upper end in the height direction orthogonal to the stacking direction.
The method for manufacturing a power storage module according to claim 10 or 11, wherein two protrusions are provided so as to line up the plurality of power storage cells in the height direction. The method for manufacturing a power storage module according to claim 12, wherein the protrusion heights of the two protrusions are different from each other. The method for manufacturing a power storage module according to claim 13, wherein one of the two protrusions located on the external terminal side has a higher protrusion height than the other protrusion. The method for manufacturing a power storage module according to any one of claims 10 to 14, wherein the plurality of protrusions have a shape including vertices when the restraining force of the restraining member is released. The power storage according to any one of claims 10 to 15, wherein one of the end plate and the restraint member provided with the plurality of protrusions is harder than the other of the end plate and the restraint member. How to make the module.

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