Method for manufacturing power storage module

Abstract

The present invention relates to a method for manufacturing a storage module. The method for manufacturing a storage module (1) comprises: a step (S10) of stacking a plurality of storage cells (100) along a first direction; a first pressurizing step (S30) of compressing the plurality of storage cells (100) along the first direction; a step (S40) of aligning the plurality of storage cells (100) in a second direction orthogonal to the first direction after releasing the pressurizing force of the first pressurizing step (S30); a second pressurizing step (S50) of compressing the plurality of storage cells (100) along the first direction after aligning the plurality of storage cells (100) in the second direction; a step (S60) of arranging a restraining part (200) on both sides of the plurality of storage cells (100) in the first direction while applying the pressurizing force of the second pressurizing step (S50); and a step (S70) of arranging the restraining part, releasing the pressurizing force of the second pressurizing step (S50), and restraining the plurality of storage cells along the first direction by the restraining part.

Description

Technical Field

[0001] The present technology relates to a method for manufacturing a power storage module. Background Art

[0002] Conventionally, there is known a battery module (power storage module) in which a plurality of battery cells (power storage cells) are stacked. Such a structure is disclosed in, for example, Japanese Patent Application Laid-Open No. 2010-272378.

[0003] If the stack is pressed in the stacking direction to constrain the stacked body when the stacked plurality of power storage cells are not sufficiently aligned, it may be difficult to correct the positions of the power storage cells to the intended positions. From the above viewpoint, the conventional structure is not necessarily sufficient. Summary of the invention

[0004] An object of the present technology is to provide a method for manufacturing a power storage module capable of accurately aligning a plurality of stacked power storage cells.

[0005] The manufacturing method of the storage battery module involved in the present technology comprises: a process of stacking a plurality of storage battery cells along a first direction (S10); a first pressurizing process of compressing the plurality of storage battery cells along the first direction (S30); a process of aligning the plurality of storage battery cells in a second direction orthogonal to the first direction after releasing the pressurizing force of the first pressurizing process (S40); a second pressurizing process of compressing the plurality of storage battery cells along the first direction after aligning the plurality of storage battery cells in the second direction (S50); a process of arranging restraints on both sides of the plurality of storage battery cells in the first direction while applying the pressurizing force of the second pressurizing process (S60); and a process of releasing the pressurizing force of the second pressurizing process after arranging the restraints and restraining the plurality of storage battery cells along the first direction (S70).

[0006] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a diagram showing the basic structure of a battery pack.

[0008] Figure 2 Yes means Figure 1 A diagram of battery cells and end plates in a battery pack is shown.

[0009] Figure 3 Yes means Figure 1 Diagram of battery cells in a battery pack shown.

[0010] Figure 4 It is a flowchart showing each process of the method for manufacturing the power storage module.

[0011] Figure 5 It is a diagram showing the steps ( S21 , S22 ) of temporary compression and temporary restriction in the width direction.

[0012] Figure 6 This is a diagram showing the step ( S23 ) of temporarily pressing the upper surface.

[0013] Figure 7 This is a diagram showing the over-compression (first time) step ( S30 ).

[0014] Figure 8 This is a diagram showing the step ( S41 ) of releasing the temporary pressing of the upper surface.

[0015] Fig. 9 It is a diagram showing the steps ( S42 , S43 ) of releasing the over-compression (first time) and restricting the width direction.

[0016] Fig.10 This is a diagram showing the step ( S44 ) of releasing the restriction in the width direction.

[0017] Fig.11 This is a diagram showing the over-compression (second time) step ( S50 ).

[0018] Fig.12 This is a diagram showing the step ( S60 ) of arranging the restraining portion.

[0019] Fig.13 This is a diagram showing the step ( S70 ) of releasing the over-compression (second time).

[0020] Fig.14 It is the residue left behind after Figure 4 A diagram illustrating traces of a battery cell during the process.

[0021] Fig.15 It is an exploded perspective view showing the structure of a battery pack.

[0022] Fig.16 It is a diagram showing the steps ( S21 , S22 ) of temporary compression and temporary restriction in the width direction.

[0023] Fig.17 This is a diagram showing the step ( S23 ) of temporarily pressing the upper surface.

[0024] Fig.18 This is a diagram showing the over-compression (first time) step ( S30 ).

[0025] Fig.19 This is a diagram showing the step ( S41 ) of releasing the temporary pressing of the upper surface.

[0026] Fig. 20It is a diagram showing the steps ( S42 , S43 ) of releasing the over-compression (first time) and restricting the width direction.

[0027] Fig.21 This is a diagram showing the step ( S44 ) of releasing the restriction in the width direction.

[0028] Fig. 22 This is a diagram showing the step ( S70 ) of releasing the over-compression (second time).

[0029] Fig.23 It is a figure which shows the housing main body which becomes a restraining part.

[0030] Fig.24 This is a diagram showing the step ( S60 ) of arranging the restraining portion.

[0031] Fig.25 This is a diagram showing the step ( S70 ) of releasing the over-compression (second time).

[0032] Fig.26 It is a diagram showing a jig for holding a battery cell.

[0033] Fig. 27 It is the residue left behind after Figure 4 A diagram illustrating traces of a battery cell during the process.

[0034] Fig.28 This is a conceptual diagram showing the characteristics of the spring constant of a battery cell.

[0035] Fig.29 This is a diagram showing an example of the relationship between the passage of time, the unit reaction force, and the unit thickness. DETAILED DESCRIPTION

[0036] Hereinafter, embodiments of the present technology will be described. It should be noted that the same reference numerals are given to the same or corresponding parts, and the description thereof may not be repeated.

[0037] It should be noted that, in the embodiments described below, when the number, amount, etc. are mentioned, the scope of the present technology is not necessarily limited to the number, amount, etc., unless otherwise specified. In addition, in the following embodiments, each component is not necessarily essential to the present technology, except for the case of special description.

[0038] It should be noted that in this specification, the descriptions of “comprise”, “include”, and “have” are open-ended, that is, including a certain structure but not excluding the inclusion of other structures other than the structure.

[0039] Figure 1 1 is a diagram showing a basic structure of the battery pack 1 . Figure 2 The diagram shows a battery cell 100 and an end plate 200 included in the battery pack 1 . Figure 3 1 is a diagram showing a battery cell 100 in the battery pack 1 .

[0040] like Figure 1 , Figure 2 As shown, a battery pack 1 as an example of a “power storage module” includes a battery cell 100 , an end plate 200 , and a restraint member 300 .

[0041] 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-metal hydride battery. In the present disclosure, the "power storage module" is not limited to the battery pack 1, and a capacitor, for example, may be used as the "power storage unit" instead of the battery cell 100.

[0042] The plurality of battery cells 100 are arranged in a manner arranged along the Y-axis direction (arrangement direction). The battery cells 100 include electrode terminals 110. A separator not shown is sandwiched between the plurality of battery cells 100. The plurality of battery cells 100 sandwiched by the two end plates 200 are pressed by the end plates 200 and constrained between the two end plates 200.

[0043] The end plates 200 are disposed at both ends of the battery pack 1 in the Y-axis direction (arrangement direction). The end plates 200 are fixed to a base such as a case that houses the battery pack 1 .

[0044] The restraining member 300 connects the two end plates 200 to each other. The restraining member 300 is mounted to the two end plates 200.

[0045] The restraining member 300 is engaged with the end plate 200 while a compressive force in the Y-axis direction is applied to the stack of the plurality of battery cells 100 and the end plate 200, and then the compressive force is released, whereby a tensile force is applied to the restraining member 300 connecting the two end plates 200. As a reaction to this, the restraining member 300 presses the two end plates 200 in a direction toward each other.

[0046] like Figure 3 As shown, the battery cell 100 is formed in a flat rectangular parallelepiped shape. The electrode terminal 110 includes a positive terminal 111 and a negative terminal 112. The electrode terminal 110 is formed on a square frame 120. The frame 120 contains an electrode body and an electrolyte solution (not shown).

[0047] Figure 4 FIG. 1 is a flowchart showing each step of a method for manufacturing a battery pack 1 (power storage module). Figure 4As shown, the manufacturing method of the battery pack 1 comprises: a process of stacking a plurality of battery cells 100 (power storage cells) along the Y-axis direction (first direction: stacking direction) (S10: stacking process); after stacking the plurality of battery cells 100, a process of temporarily aligning the plurality of battery cells 100 in the X-axis direction (second direction: width direction) orthogonal to the Y-axis direction (S20); a first over-compression process of compressing the plurality of battery cells 100 to an over-compression region along the Y-axis direction (S30: first pressurizing process); after releasing the pressurizing force of the first over-compression process, aligning the plurality of battery cells 100 in the X-axis direction a second over-compression process (S50: a second pressurizing process) of compressing the multiple battery cells 100 to the over-compression area along the Y-axis direction after aligning the multiple battery cells 100 in the X-axis direction; a process of configuring the restraint components 300 on both sides of the Y-axis direction relative to the multiple battery cells 100 while applying the pressure of the second over-compression process (S60); and a process of releasing the pressure of the second over-compression process after configuring the restraint components 300, and constraining the multiple battery cells 100 along the Y-axis direction by the restraint components 300 (S70).

[0048] The process (S20) of temporarily aligning the battery cells 100 in the X-axis direction includes: a temporary compression process (S21), a temporary restriction process in the width direction (S22), and a temporary pressing process on the upper surface (S23). The process (S40) of aligning the battery cells 100 in the X-axis direction includes: a release process of temporarily pressing the upper surface (S41), a release process of over-compression (first time) (S42), a restriction process in the width direction (S43), and a release process of the restriction process in the width direction (S44).

[0049] Figure 5 2 is a diagram showing a process (S21) of temporary compression in the Y-axis direction (stacking direction) and a process (S22) of temporary restriction in the X-axis direction (width direction). Figure 5 As shown, a compressive force is applied to the stack of the battery cell 100 and the end plate 200 by the jig 400. At this time, the frame 120 of the battery cell 100 is slightly expanded due to the internal gas pressure.

[0050] In addition, the jig 500 is used to temporarily align the plurality of battery cells 100 along the X-axis direction. The jig 500 includes a first component 510 and a second component 520. By moving the second component 520 toward the first component 510 in the direction of arrow X1, the plurality of battery cells 100 are temporarily aligned in the X-axis direction. However, since the battery cell 100 is in an expanded state, even if the battery cell 100 is clamped by the first component 510 and the second component 520, the plurality of battery cells 100 are not completely aligned in the X-axis direction.

[0051] Figure 6 2 is a diagram showing the process (S23) of temporarily pressing the upper surface after temporary restriction in the X-axis direction. Figure 6 As shown, the stack of battery cells 100 and end plates 200 is clamped in the Z-axis direction by a jig 600. The jig 600 includes a first component 610 and a second component 620. The upper surfaces of the plurality of battery cells 100 are temporarily pressed by moving the second component 620 toward the first component 610 in the arrow Z1 direction.

[0052] Figure 7 is a diagram showing the process (S30) of over-compression (first time). Figure 7 As shown, the battery cells 100 are compressed into a substantially rectangular parallelepiped shape by applying a compressive force (arrows Y1 and Y2) in the Y-axis direction by the jig 400. At this time, the upper surfaces of the plurality of battery cells 100 are temporarily pressed.

[0053] Here, "over-compression" refers to a state in which the electrode body contained in the frame 120 is compressed and deformed. When the compression is released from this state, the electrode body returns to its original shape. However, since the electrode body temporarily maintains the compressed shape, it takes time to gradually return to its original shape.

[0054] Next, use Figure 8~Figure 10 , the step ( S40 ) of aligning the plurality of battery cells 100 will be described. Figure 8 2 is a diagram showing a step ( S41 ) of releasing the temporary pressure on the upper surface. Fig. 9 2 is a diagram showing the steps (S42, S43) of releasing the over-compression (first time) and limiting the width direction. Fig.10 This is a diagram showing the step ( S44 ) of releasing the restriction in the width direction.

[0055] like Figure 8 As shown in FIG. 1 , the second component 620 of the clamp 600 moves in the direction of arrow Z2 and is separated from the battery cell 100 ( S41 ). Fig. 9 As shown, the compressive force of the clamp 400 is released (S42). At this time, before the frame 120 of the battery cell 100 returns to its original shape (slightly expanded state), the first component 510 of the clamp 500 is moved in the direction of the arrow X1 to align the multiple battery cells 100 in the X-axis direction (S43). Since the frame 120 maintains a rectangular parallelepiped shape, accurate alignment can be performed. Here, pressing components 510A and 520A are respectively provided on the surfaces of the first component 510 and the second component 520 of the clamp 500.

[0056] After the X-axis direction of the plurality of battery cells 100 is aligned, Fig.10As shown, the second member of the jig 500 moves in the direction of arrow X2 to release the restriction force in the width direction (X-axis direction) ( S44 ).

[0057] Fig.11 This is a diagram showing the over-compression (second time) step ( S50 ). Fig.12 This is a diagram showing the step ( S60 ) of arranging the restraint member 300 . Fig.13 This is a diagram showing the step ( S70 ) of releasing the over-compression (second time).

[0058] like Fig.11 As shown in FIG. 1 , the second over-compression process is performed in a state where the upper surface of the battery cell 100 is pressed by the third member 630 with a roller 630A. Fig.12 As shown, the restraining member 300 is arranged in a state where the over-compression state is maintained. Fig.13 As shown, the jig 400 is moved in the direction of arrows Y1, Y2 or one of them to release the over-compression state, thereby increasing the axial length of the stack of battery cells 100 and end plates 200A and being constrained by the constraining member 300 in the stacking direction.

[0059] Fig.14 The figure is a diagram for explaining the traces remaining on the battery cells 100. According to the manufacturing method of the battery pack 1 of the present embodiment, since the over-compression process is performed twice, the recessed portion 100A corresponding to the shape of the separator disposed between the plurality of battery cells 100 is formed on the surface of the battery cells 100 in the stacking direction.

[0060] Next, as a modification of the “constraint portion”, a structure directly supported by the housing 700 instead of the constraining member 300 will be described.

[0061] Fig.15 2 is an exploded perspective view showing the structure of the battery pack 2 . The battery pack 2 includes a battery cell 100 , a case 700 (sealed case), and a heat conductor 800 .

[0062] A plurality of battery cells 100 (power storage cells) are stacked along the Y-axis direction (stacking direction). The housing 700 includes a housing body 710 and a cover member 720. The housing body 710 constitutes the bottom surface and the side surface of the housing 700. The cover member 720 constitutes the upper surface of the housing 700. The housing body 710 has an opening on the upper side (the electrode terminal 110 side) of the plurality of battery cells 100. The cover member 720 is provided on the opening of the housing body 710.

[0063] The housing 700 has an internal space for accommodating the stack of battery cells 100. The housing body 710 and the cover member 720 may be, for example, a cast member (die casting) made of a metal material such as aluminum or magnesium, or a stamped member made of a carbon-containing raw material. The housing 700 is not limited to the above-mentioned form, as long as it meets the prescribed characteristics in terms of strength, heat dissipation, thermal conductivity, etc. For example, the housing body 710 and the cover member 720 may be made of resin.

[0064] The joint between the housing body 710 and the cover member 720 can be sealed using a sealing material such as rubber, an adhesive, a hot melt material, etc., or the two can be joined by ultrasonic welding, laser welding, etc. Thus, a closed space is formed inside the housing 700 composed of the housing body 710 and the cover member 720.

[0065] The heat conductor 800 is disposed between the battery cell 100 and the housing body 710 of the housing 700 , and promotes the transfer of heat generated in the battery cell 100 to the housing 700 .

[0066] The battery pack 2 can be mounted on a vehicle. When the battery pack 2 is mounted on a vehicle, typically, the cover member 720 is located above the case body 710. In this specification, the Z-axis direction is sometimes referred to as the "upper and lower directions", the case body 710 side in the Z-axis direction is referred to as the "lower side", and the cover member 720 side is referred to as the "upper side".

[0067] In the battery pack 2 , the stack of battery cells 100 is compressed and restrained in the Y-axis direction (stacking direction) by the case body 710 .

[0068] Fig.16 2 is a diagram showing a process (S21) of temporary compression in the Y-axis direction (stacking direction) and a process (S22) of temporary restriction in the X-axis direction (width direction). Fig.16 As shown, the clamp 400A applies a compressive force to the stack of the battery cell 100 and the end plate 200A. At this time, the frame 120 of the battery cell 100 is slightly expanded due to the internal gas pressure.

[0069] In addition, the jig 500 is used to temporarily align the plurality of battery cells 100 along the X-axis direction. The jig 500 includes a first component 510 and a second component 520. By moving the second component 520 toward the first component 510 in the direction of arrow X1, the plurality of battery cells 100 are temporarily aligned in the X-axis direction. However, since the battery cell 100 is in an expanded state, even if the battery cell 100 is clamped by the first component 510 and the second component 520, the plurality of battery cells 100 are not completely aligned in the X-axis direction.

[0070] Fig.17 2 is a diagram showing the process (S23) of temporarily pressing the upper surface after temporary restriction in the X-axis direction. Fig.17 As shown, the stack of battery cells 100 and end plates 200A is clamped in the Z-axis direction by a jig 600. The jig 600 includes a first component 610 and a second component 620. The upper surfaces of the plurality of battery cells 100 are temporarily pressed by moving the second component 620 toward the first component 610 in the arrow Z1 direction.

[0071] Fig.18 is a diagram showing the process (S30) of over-compression (first time). Fig.18 As shown, the clamp 400A applies a compressive force in the Y-axis direction (arrows Y1 and Y2), and the battery cells 100 are compressed into a substantially rectangular parallelepiped shape. At this time, the upper surfaces of the plurality of battery cells 100 are temporarily pressed.

[0072] Next, use Figure 19~Figure 21 , the step ( S40 ) of aligning the plurality of battery cells 100 will be described. Fig.19 2 is a diagram showing a step ( S41 ) of releasing the temporary pressure on the upper surface. Fig. 20 2 is a diagram showing the steps (S42, S43) of releasing the over-compression (first time) and limiting the width direction. Fig.21 This is a diagram showing the step ( S44 ) of releasing the restriction in the width direction.

[0073] like Fig.19 As shown in FIG. 1 , the second component 620 of the clamp 600 moves in the direction of arrow Z2 and is separated from the battery cell 100 ( S41 ). Fig. 20 As shown, the compressive force of the clamp 400A is released (S42). At this time, before the frame 120 of the battery cell 100 returns to its original shape (slightly expanded state), the first component 510 of the clamp 500 is moved in the direction of the arrow X1 to align the multiple battery cells 100 in the X-axis direction (S43). Since the frame 120 maintains a rectangular parallelepiped shape, accurate alignment can be performed. Here, pressing components 510A and 520A are respectively provided on the surfaces of the first component 510 and the second component 520 of the clamp 500.

[0074] After the X-axis direction of the plurality of battery cells 100 is aligned, Fig.21 As shown, the second member of the jig 500 moves in the direction of arrow X2 to release the restriction force in the width direction (X-axis direction) ( S44 ).

[0075] Fig. 22 This is a diagram showing the over-compression (second time) step ( S50 ). Fig.23 This is a diagram showing a housing body 710 serving as a “constraint portion”. Fig.24 This is a diagram showing a step ( S60 ) of arranging the housing 700 as a restraining portion. Fig.26 This is a diagram showing the step ( S70 ) of releasing the over-compression (second time).

[0076] like Fig. 22 As shown in FIG. 1 , the second over-compression process is performed in a state where the upper surface of the battery cell 100 is pressed by the third member 630 with a roller 630A. Fig.23 As shown, the housing body 710 has a recess 710A into which the jig 400A can be inserted while holding a plurality of battery cells 100. Fig.24 As shown, the jig 400A is inserted into the recess 710A while maintaining the over-compression state. Thus, the housing body 710 as a "constraint" is arranged on both ends of the stack of the battery cell 100 and the end plate 200A. From this state, the jig 400A is moved in the Z-axis direction (with respect to the Z axis). Fig.24 The over-compression state is released, whereby the axial length of the stack of battery cells 100 and end plates 200A is expanded and constrained by the wall surface of the shell body 710 in the stacking direction.

[0077] Fig.26 , Fig. 27 1 is a diagram for explaining traces remaining in the battery cell 100. Fig.26 As shown, the stack of battery cells 100 is compressed twice by the jig 400A via the thin end plates 200A. Therefore, recessed portions 100B corresponding to the shape of the jig 400A are formed on the surface of the battery cells 100 in the stacking direction.

[0078] Fig.28 is a conceptual diagram showing the characteristics of the spring constant of the battery cell 100. Fig.28 As shown, the battery cell 100 has a characteristic that as the stack length becomes smaller, the slope of the cell reaction force-stack length (the “spring constant” of the battery cell 100 ) becomes larger.

[0079] The two curves ( Fig.28 The part between the two dotted lines in Fig.28 Set the length of "Constraint internal dimension" so that "A" in (a) is within the "Constraint load allowable range".

[0080] Fig.29 is a diagram showing an example of the relationship between the passage of time, the unit reaction force, and the unit thickness. Fig.29As shown, in the first over-compression process (S30), the cell thickness 20 decreases with the increase of the cell reaction force 10. Afterwards, if the over-compression is released (S42) in the process of aligning multiple battery cells 100 (S40), the cell thickness 20 increases over a certain period of time. During this period, the X-axis direction of multiple battery cells 100 can be aligned (S43). Afterwards, in the second over-compression process (S50), the cell thickness 20 decreases with the increase of the cell reaction force 10. Thus, the configuration of the restraining member 300 or the shell body 710 can be performed.

[0081] According to the manufacturing method of the battery pack 1 of the present embodiment, after the first over-compression process (S30), the battery cell 100 is aligned in the X-axis direction in a state where the compression force is released, so that the alignment in the X-axis direction can be accurately performed. In addition, since the first and second over-compression processes (S30, S50) are performed in a state where the upper surface of the battery cell 100 is pressed, the alignment in the Z-axis direction can also be accurately performed. Therefore, a battery pack 1 can be obtained in which the alignment of multiple battery cells 100 in the X-axis direction and the Z-axis direction in addition to the Y-axis direction is accurately performed. By accurately aligning multiple battery cells 100 in the three-axis direction, busbar bonding between multiple battery cells 100 can be stably and reliably performed.

[0082] It should be noted that the first and second over-compression steps (S30, S50) do not necessarily need to reach an over-compression state in which the electrode body is deformed. As long as they are close to an over-compression state and the time for reducing the cell thickness is ensured only during the alignment of the battery cell 100 in the X-axis direction, they are included in the scope of the present technology.

[0083] Although the embodiments of the present invention have been described, the embodiments disclosed this time should be understood to be illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A method for manufacturing a power storage module, wherein: The method for manufacturing the power storage module comprises: A step of stacking a plurality of power storage units along a first direction (S10), wherein the plurality of power storage units each include a square frame and each is formed in a flat rectangular parallelepiped shape, and the first direction is a short side direction of the frame; After stacking the plurality of storage cells, a step of temporarily aligning the cells in a second direction orthogonal to the first direction is performed ( S20 ), the second direction being a longitudinal direction of the frame body; A first pressurizing step (S30) of compressing the plurality of power storage cells along the first direction; After the pressing force of the first pressing step is released, a step of aligning the plurality of power storage cells in the second direction is performed ( S40 ); After aligning the plurality of storage cells in the second direction, a second pressurizing step ( S50 ) of compressing the plurality of storage cells along the first direction; a step of arranging restraint portions on both sides of the plurality of power storage cells in the first direction while applying the pressing force of the second pressing step ( S60 ); and After the constraining portion is disposed, the pressing force of the second pressing step is released, and the constraining portion constrains the plurality of power storage cells along the first direction ( S70 ), The process (S20) of temporarily aligning the second direction includes: a process (S21) of temporarily compressing, a process (S22) of temporarily restricting the width direction, and a process (S23) of temporarily pressing the upper surface. The step (S40) of aligning the plurality of power storage cells in the second direction includes: a step (S41) of releasing the temporary pressing of the upper surface, a step (S42) of releasing the over-compression, a step (S43) of limiting the width direction, and a step (S44) of releasing the limiting the width direction. The plurality of power storage units each include a positive terminal and a negative terminal, The second direction is a direction in which the positive electrode terminal and the negative electrode terminal are arranged.

2. The method for manufacturing a power storage module according to claim 1, wherein: In the first pressurizing step, the plurality of electricity storage cells are compressed to an over-compression region.

3. The method for manufacturing a power storage module according to claim 1 or 2, wherein: In the second pressurizing step, the plurality of electricity storage cells are compressed to an over-compression region.

Images