Electricity storage device and method for manufacturing the same

Abstract

To provide a power storage device which can elastically compress an electrode laminate unit of an electrode body by the power storage device itself and can prevent an impregnated electrolyte in the electrode body from flowing to the outside of the electrode body.SOLUTION: A power storage device 1 has a case 10 including: a bottomed angular cylindrical body member 21 forming a second main wall part 12 and four side wall parts 13 to 16; and a rectangular lid member 31 forming a first main wall part 11, the main wall part 11 and the second main wall part 12 elastically compressing an electrode laminate unit 50e of an electrode body 50. The case 10 has a plurality of bending protruding parts 41, 42, 46, and 47 having a shape of extending to an upper-side AH1 in an inner side DH3 of the direction of an axial line, bending, and extending to an outer side DH4 of the direction of an axial line, the bending protruding parts pressing the electrode laminate unit 50e and restricting moving of an impregnated electrolyte 3a to a lower part 50ega of both end parts 50eg of the electrode laminate unit 50e.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a rectangular electricity storage device in which an electrode assembly is housed in a rectangular box-shaped case, and to a method for manufacturing the electricity storage device. [Background technology]

[0002] Among prismatic batteries in which an electrode assembly is housed in a rectangular box-shaped case, batteries that are mounted on vehicles and used for long periods of time are generally externally restrained using external restraining members consisting of a pair of end plates and multiple restraining bands for reasons such as improving charge / discharge cycle characteristics. As a result, in a battery in which a flat wound electrode assembly is housed in a case, the electrode stack portion of the electrode assembly, in which a positive electrode plate, a negative electrode plate, and a separator are stacked in a flat plate shape, is pressed in the thickness direction of the electrode assembly. Related prior art includes, for example, Patent Document 1 (see Figure 1, etc., of Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-173893 Summary of the Invention [Problem to be solved by the invention]

[0004] However, externally restraining a battery using a restraining member poses problems such as increased costs, increased size, increased weight, and an increased number of parts. Another problem is that as the battery is used, the impregnated electrolyte impregnated in the electrode body is pushed out of the electrode body, reducing the amount of impregnated electrolyte available for charge and discharge. That is, the electrode body expands and contracts with charge and discharge. When the electrode body expands inside the case, the impregnated electrolyte is pushed out of the electrode body through both ends of the electrode body in the axial direction. This reduces the amount of impregnated electrolyte available for charge and discharge, resulting in a decrease in battery capacity and an increase in battery resistance.

[0005] The present invention has been made in consideration of the current situation, and provides an electricity storage device in which the electrode stack portion of a flat wound electrode body is elastically compressed in the thickness direction of the electrode body by the electricity storage device itself, and which can prevent the impregnated electrolyte in the electrode body from leaking out of the electrode body as the electricity storage device is used, and a method for manufacturing the electricity storage device. [Means for solving the problem]

[0006] (1) One aspect of the present invention for solving the above problem provides a storage battery comprising: a case; an electrode assembly housed in the case; and an impregnated electrolyte impregnated in the electrode assembly, wherein the case is shaped like a rectangular parallelepiped box and has a rectangular first main wall portion, a rectangular second main wall portion facing the first main wall portion, and four rectangular side walls connecting the first main wall portion and the second main wall portion and extending in a thickness direction of the case, the electrode assembly is a flat wound type in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound in a flat shape with a pair of strip-shaped separators interposed therebetween, the positive electrode plate, the negative electrode plate, and the separator have a rectangular parallelepiped electrode stack portion in which the positive electrode plate, the negative electrode plate, and the separator are stacked in a flat shape in the thickness direction of the electrode assembly, and the storage battery is housed in the case with the thickness direction of the electrode assembly parallel to the thickness direction of the case. the case includes a main body member that is a rectangular cylindrical body with a bottom, the main body member forming the second main wall portion and the four side wall portions, and having a rectangular opening constituted by the four side wall portions; and a rectangular lid member that is the first main wall portion, the lid peripheral portion being joined to an opening peripheral portion of the opening of the main body member around the entire circumference, the first main wall portion and the second main wall portion of the case elastically compressing the electrode stack portion of the electrode body in the electrode body thickness direction, and the first main wall portion and the second main wall portion of the case elastically compress the electrode stack portion of the electrode body in the electrode body thickness direction, and the case includes a plurality of bent ridge portions that protrude inward in the thickness direction of the case, and when the electric storage device is placed in a position where the electrode body axial direction and the electrode body thickness direction are parallel to the horizontal direction, the ridge portions protrude inward in the axial direction of the electrode body axial direction. in lower side Part of Extending upward from Then, the more you go upwards On the outside in the axial direction of the electrode body To face a shape in which the shaft is bent and further extends outward in the axial direction; and / or , the inner side in the axial direction Part of from , first, the higher Outward in the axial direction To face The energy storage device has a plurality of curved ridges that are curved and further extend outward in the axial direction, and that press the electrode stack portion of the electrode body in the thickness direction of the electrode body through elastic compression by the first main wall portion and the second main wall portion, thereby restricting the impregnated electrolyte from moving to below both end portions of the electrode stack portion in the axial direction of the electrode body.

[0007] In the above-described electricity storage device, the first and second main walls of the case elastically compress the electrode stack of the electrode body in the thickness direction of the electrode body. That is, this electricity storage device is a self-compressing type in which the electrode stack of the electrode body is elastically compressed by the electricity storage device itself. Therefore, when using the electricity storage device, it is not necessary to use a separate restraining member, or external restraint by a simple restraining member is sufficient. Furthermore, in the above-mentioned energy storage device, the case is formed by joining a lid member forming the first main wall portion to a main body member forming the second main wall portion and four side wall portions, so that a self-compressing energy storage device can be easily manufactured as described below, and an inexpensive energy storage device can be produced.

[0008] Furthermore, when an energy storage device is used in a position where the axial direction and thickness direction of the electrode body are parallel to the horizontal, it has been found that the impregnated electrolyte that flows out of the electrode body from within the electrode body as the electrode body is charged and discharged is particularly likely to flow out from the lower ends of both ends of the electrode stack in the axial direction of the electrode body. In contrast, the above-mentioned electricity storage device is in lower side Part of Extending upward from Next, the upper part is oriented outward in the axial direction. A bent shape extending outward in the axial direction; and / or , axially inward Part of from First, the more you go up, the more the shaft is pointing outwards.The electrode assembly has a plurality of curved ridges that are curved and extend outward in the axial direction and press against the electrode stack, restricting the impregnating electrolyte from migrating to the lower portions of both ends of the electrode stack. Pressing the electrode stack with these curved ridges makes it difficult for the impregnating electrolyte to move from the upper side to the lower side and from the inside in the axial direction to the outside in the axial direction, thereby preventing the impregnating electrolyte from migrating to the lower portions of both ends of the electrode stack. Therefore, it is possible to prevent the impregnating electrolyte from leaking out of the electrode assembly through the lower portions of both ends of the electrode assembly as the electricity storage device is used.

[0009] Examples of the "electricity storage device" include secondary batteries such as lithium ion secondary batteries, capacitors such as lithium ion capacitors, and all-solid-state batteries. The "bent ridges" can be provided on at least one of the first and second main walls of the case. Alternatively, an intervening member made of metal or resin can be disposed between the first main wall of the case and the electrode stacking portion of the electrode body, or between the second main wall of the case and the electrode stacking portion of the electrode body, and the bent ridges can be provided on this intervening member. The first main wall portion, the second main wall portion, and the intervening member may be provided with only the bent ridge portions, or may be provided with convex portions having a different shape from the bent ridge portions in addition to the bent ridge portions.

[0010] (2) Furthermore, the energy storage device described in (1) may be an energy storage device that includes an intervening member at least between the first main wall portion of the case and the electrode stack portion of the electrode body, and between the second main wall portion of the case and the electrode stack portion of the electrode body, and the plurality of curved ridge portions are preferably provided on the intervening member.

[0011] In the above-described electricity storage device, an intervening member is disposed at least between the first main wall portion of the case and the electrode stack portion of the electrode body and between the second main wall portion of the case and the electrode stack portion of the electrode body, and the above-described curved ridge portion is provided on this intervening member, which eliminates the need to provide a curved ridge portion on the first main wall portion or the second main wall portion of the case.

[0012] (3) Furthermore, in the electricity storage device according to (1), the plurality of bent ridges may be provided on at least one of the first main wall and the second main wall of the case.

[0013] In the above-mentioned energy storage device, a curved ridge portion is provided on at least one of the first main wall portion and the second main wall portion of the case, so there is no need to place an intervening member having a curved ridge portion between the first main wall portion or the second main wall portion of the case and the electrode body, and the number of parts can be reduced.

[0014] (4) Yet another aspect is a battery comprising a case, an electrode assembly housed in the case, and an impregnated electrolyte impregnated in the electrode assembly, wherein the case is a rectangular box-shaped case having a rectangular first main wall portion, a rectangular second main wall portion facing the first main wall portion, and four rectangular side wall portions connecting the first main wall portion and the second main wall portion and extending in the case thickness direction, the electrode assembly being a flat wound type in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound in a flat shape with a pair of strip-shaped separators interposed therebetween, the battery having a rectangular parallelepiped electrode stack portion in which the positive electrode plate, the negative electrode plate, and the separator are stacked in a flat shape in the electrode assembly thickness direction, and the battery is housed in the case with the electrode assembly thickness direction parallel to the case thickness direction. An electricity storage device comprising: The case has a base-closed rectangular cylindrical main body member that forms the second main wall portion and the four side wall portions and has a rectangular opening constituted by the four side wall portions, and a rectangular lid member that forms the first main wall portion and has a lid peripheral portion joined to the opening peripheral portion of the opening of the main body member around the entire circumference, and the first main wall portion and the second main wall portion of the case elastically compress the electrode stack portion of the electrode body in the electrode body thickness direction, and the case has a plurality of bent ridge portions that protrude inward in the thickness direction of the case thickness direction, and when the power storage device is placed in a position where the electrode body axial direction and the electrode body thickness direction of the electrode body are parallel to the horizontal direction, in lower side Part of Extending upward from Then, the more you go upwards On the outside in the axial direction of the electrode body To facea shape in which the shaft is bent and further extends outward in the axial direction; and / or , the inner side in the axial direction Part of from , first, the higher Outward in the axial direction To face a pressing and compressing step of placing the cover member on the electrode body accommodated in the main body member and applying an external force to the first main wall portion formed by the cover member and the second main wall portion of the main body member to press and compress the electrode stack portion of the electrode body in the thickness direction of the electrode body; a joining step of joining the cover peripheral portion of the cover member to the opening peripheral portion of the opening of the main body member around the entire circumference while the electrode body is pressed and compressed, thereby forming the case; and a releasing step of releasing the external force after the joining step.

[0015] In conventional prismatic batteries, the case is composed of a bottomed, rectangular cylindrical body member that forms the first and second main walls and three side walls of the case, and a lid member that forms one side wall. It is difficult to manufacture a self-compressing battery with this type of battery. The gap between the first and second main walls of the body member is narrower than the thickness of the electrode body, or, in the case of a battery with the aforementioned intervening member, the combined thickness of the electrode body and the intervening member, in order to press and compress the electrode stack of the electrode body in the assembled battery. This makes it difficult to insert the electrode body, etc., into the body member.

[0016] In contrast, in the manufacturing method of the above-mentioned electricity storage device, in the housing step, the electrode assembly is first housed in a main body member having a bottomed rectangular tubular shape that forms a second main wall portion and four side walls, so that the electrode assembly can be easily housed in the main body member. Then, by performing the above-mentioned pressing and compressing step, joining step, and releasing step, it is possible to easily manufacture a self-compressing electricity storage device in which the electrode stack portion of the electrode assembly is elastically compressed by the electricity storage device itself.

[0017] In addition, examples of the method for joining the cover member to the main body member in the "joining step" include joining by welding such as laser welding, and joining by crimping.

[0018] (5) Further, in the method for manufacturing an electric storage device described in (4), the electric storage device may include an intervening member at least between the first main wall portion of the case and the electrode stacking portion of the electrode body, and between the second main wall portion of the case and the electrode stacking portion of the electrode body, and the plurality of bent ridge portions are provided on the intervening member, and the accommodating step may accommodate the electrode body and the intervening member in the main body member with the intervening member overlapping the electrode stacking portion of the electrode body, and the pressing and compressing step may press the electrode stacking portion of the electrode body and the intervening member in the thickness direction of the electrode body.

[0019] In the method for manufacturing an electricity storage device described above, an electricity storage device is manufactured using the above-described intervening member, and therefore an electricity storage device can be manufactured in which the bent ridges of the intervening member appropriately press against the electrode stack portion of the electrode assembly.

[0020] (6) Furthermore, in the method for manufacturing an electric storage device described in (4), the plurality of bent ridge portions may be provided on at least one of the first main wall portion and the second main wall portion of the case, and the pressing and compressing step may be a method for manufacturing an electric storage device in which the bent ridge portions provided on the case press the electrode stack portion of the electrode body in the thickness direction of the electrode body.

[0021] In the method for manufacturing the electricity storage device described above, the insertion step and the pressing and compressing step can be easily performed by not disposing the intervening member forming the bent ridge portion inside the main body member. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a perspective view of a battery according to a first embodiment. [Figure 2] FIG. 1 is an exploded perspective view of a battery according to a first embodiment. [Figure 3] 1 and 4 along the case width direction and case thickness direction of the battery according to Embodiment 1. FIG. [Figure 4] 2 is a plan view of the battery according to Embodiment 1, seen from the inner side in the thickness direction of an interposition member. FIG. [Figure 5] FIG. 1 is a perspective view of an electrode assembly according to a first embodiment. [Figure 6] 2 is a flowchart of a method for manufacturing a battery according to the first embodiment. [Figure 7] 4 is an explanatory view showing a state in which an electrode body and an interposition member are accommodated in a main body member in an accommodating step in the manufacturing method of the battery according to the first embodiment. FIG. [Figure 8] 4 is an explanatory view showing how an external force is applied to press the electrode stacking portion and the interposed member of the electrode assembly in the thickness direction of the electrode assembly in a press-compression step in the manufacturing method of the battery according to the first embodiment. FIG. [Figure 9] 4 is an explanatory view showing how the lid peripheral portion of the lid member is laser-welded to the opening peripheral portion of the body member in a joining step in the manufacturing method of the battery according to Embodiment 1. FIG. [Figure 10] 4 is a cross-sectional view corresponding to FIG. 3 taken along the case width direction and case thickness direction of the battery according to Embodiment 2. FIG. [Figure 11] 10 is a plan view of the battery according to Embodiment 2, seen from the inside in the thickness direction of the lid member. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0023] (Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a perspective view of a battery (energy storage device) 1 according to this first embodiment, FIG. 2 shows an exploded perspective view of the battery 1, and FIG. 3 shows a cross-sectional view of the battery 1. FIG. 4 shows a plan view of the battery 1 as seen from the inner side CH3 in the thickness direction of the interposition members 40 and 45. FIG. 5 shows a perspective view of an electrode assembly 50. In the following description, the case height direction AH, case width direction BH, case thickness direction CH, electrode assembly axial direction DH, electrode assembly width direction EH, and electrode assembly thickness direction FH will be defined as the directions shown in FIGS. 1 to 5. The battery 1 is a sealed, rectangular (rectangular) lithium-ion secondary battery that is installed in vehicles such as hybrid cars, plug-in hybrid cars, and electric vehicles. When the battery 1 is used, it is positioned so that the case width direction BH (electrode assembly axial direction DH) and case thickness direction CH (electrode assembly thickness direction FH) are parallel to the horizontal direction IH.

[0024] The battery 1 is composed of a case 10, a flat wound electrode assembly 50 housed in the case 10, and a positive electrode terminal 60 and a negative electrode terminal 70 each supported by the case 10. The electrode assembly 50 is covered in a bag-shaped insulating holder (not shown) made of insulating film within the case 10. Two intervening members 40, 45 are also housed within the case 10, overlapping the electrode assembly 50 (see FIGS. 2 to 4, not shown in FIG. 1). The case 10 also contains an electrolyte 3, a portion of which is impregnated into the electrode assembly 50 as an impregnated electrolyte 3a, and the remainder is pooled on the second side wall 14, which is the lower wall of the case 10.

[0025] Of these, the case 10 is made of metal (aluminum in the present embodiment 1). The case 10 is in the shape of a rectangular parallelepiped box, and has a first main wall portion 11, a second main wall portion 12, and four side walls 13 to 16 (first side wall portion 13, second side wall portion 14, third side wall portion 15, and fourth side wall portion 16), each of which has a rectangular plate shape. The first main wall portion 11 and the second main wall portion 12 have a larger area than the side wall portions 13 to 16. The first main wall portion 11 and the second main wall portion 12 face each other, with the first main wall portion 11 located on one side CH1 in the case thickness direction CH (the front right side in FIGS. 1 and 2, the upper side in FIG. 3), and the second main wall portion 12 located on the other side CH2 in the case thickness direction CH (the rear left side in FIGS. 1 and 2, the lower side in FIG. 3).

[0026] Meanwhile, the side walls 13-16 each extend in the case thickness direction CH, connecting the first main wall 11 and the second main wall 12. The first side wall 13 and the second side wall 14 face each other, with the first side wall 13 located on an upper side AH1 in the case height direction AH and the second side wall 14 located on a lower side AH2 in the case height direction AH. The third side wall 15 and the fourth side wall 16 face each other, with the third side wall 15 located on one side BH1 in the case width direction BH and the fourth side wall 16 located on the other side BH2 in the case width direction BH.

[0027] First side wall 13, which is also the top wall of case 10, is provided with safety valve 17 that ruptures and opens when the internal pressure of case 10 exceeds the valve opening pressure. First side wall 13 is also provided with liquid injection hole 13k that communicates between the inside and outside of case 10, and is airtightly sealed with a disk-shaped sealing member 18 made of aluminum. Furthermore, a positive electrode terminal 60 is fixed to the first side wall 13 near an end of one side BH1 in the case width direction BH. Specifically, the positive electrode terminal 60 is formed by crimping a plurality of metal members made of aluminum, and is fixed to the first side wall 13 in a state insulated from the first side wall 13 via a resin portion 65 made of a plurality of resin members. This positive electrode terminal 60 is connected to and conductively connected to the positive electrode current collecting portion 50c of the electrode body 50 inside the case 10, and also extends through the first side wall 13 to the outside of the battery.

[0028] A negative electrode terminal 70 is fixed to the first side wall 13 near an end portion on the other side BH2 in the case width direction BH. Specifically, the negative electrode terminal 70 is formed by crimping a plurality of metal members made of copper, and is fixed to the first side wall 13 in a state insulated from the first side wall 13 via a resin portion 75 made of a plurality of resin members. The negative electrode terminal 70 is connected to and conductively connected to the negative electrode current collecting portion 50d of the electrode body 50 inside the case 10, and also extends through the first side wall 13 to the outside of the battery.

[0029] The case 10 is composed of a main body member 21 in the shape of a rectangular cylinder with a bottom and a rectangular opening 21c, and a rectangular plate-like lid member 31. Of these, the main body member 21 forms the second main wall portion 12 and four side wall portions 13 to 16 described above, and the opening 21c of the main body member 21 is composed of the four side wall portions 13 to 16. On the other hand, the lid member 31 forms the first main wall portion 11 described above, and closes the opening 21c of the main body member 21. Specifically, the lid peripheral portion 31f of the lid member 31 is joined (welded) around the entire periphery to the opening peripheral portion 21f of the opening 21c of the main body member 21.

[0030] Next, the electrode assembly 50 will be described (see FIGS. 1 to 3 and 5). This electrode assembly 50 is formed by stacking a strip-shaped positive electrode plate 51 and a strip-shaped negative electrode plate 54 with a pair of strip-shaped separators 57 made of porous resin films in between, winding them into a cylindrical shape around the winding axis DX, and then pressing them into a flat shape. That is, the electrode assembly 50 has a pair of electrode R portions 50r located at both ends in the electrode assembly width direction EH, and an electrode stacking portion 50e located therebetween. The electrode R portion 50r is a portion where the positive electrode plate 51, the negative electrode plate 54, and the separator 57 are stacked while being bent into a semi-cylindrical shape. Meanwhile, the electrode stacking portion 50e is a rectangular parallelepiped portion where the positive electrode plate 51, the negative electrode plate 54, and the separator 57 are stacked in a flat plate shape in the electrode assembly thickness direction FH. Furthermore, the electrode body 50 has a positive electrode current collecting portion 50c (described later) at an end on one side DH1 in the electrode body axial direction DH along the winding axis DX, and a negative electrode current collecting portion 50d (described later) at an end on the other side DH2 in the electrode body axial direction DH.

[0031] The electrode assembly 50 is housed in the case 10 with the electrode assembly axial direction DH parallel to the case width direction BH, the electrode assembly width direction EH parallel to the case height direction AH, and the electrode assembly thickness direction FH parallel to the case thickness direction CH. The electrode assembly 50 is housed in the case 10 with the electrode laminated portion 50e compressed in the electrode assembly thickness direction FH (case thickness direction CH). In other words, the battery 1 is a self-compressing battery, in which the case 10 elastically deforms and the first main wall portion 11 and second main wall portion 12 of the case 10 elastically compress the electrode laminated portion 50e in the electrode assembly thickness direction FH.

[0032] The positive electrode plate 51 has a positive electrode current collector foil 52 made of a strip-shaped aluminum foil. On both main surfaces of the positive electrode current collector foil 52, a strip-shaped positive electrode active material layer 53 containing positive electrode active material particles capable of absorbing and releasing lithium ions is formed. At one end of the positive electrode plate 51 in the width direction, the positive electrode active material layer 53 is not present on the positive electrode current collector foil 52, and the positive electrode current collector foil 52 is exposed. In the electrode assembly 50, the exposed portion of the positive electrode current collector foil 52 protrudes in a spiral shape from the electrode laminate portion 50e to one side DH1 in the electrode assembly axial direction DH, forming the aforementioned positive electrode current collector portion 50c. The positive electrode current collector portion 50c is connected to the positive electrode terminal 60.

[0033] The negative electrode plate 54 has a negative electrode current collector foil 55 made of a strip-shaped copper foil. A strip-shaped negative electrode active material layer 56 containing negative electrode active material particles capable of absorbing and releasing lithium ions is formed on each of the two main surfaces of the negative electrode current collector foil 55. At one end of the negative electrode plate 54 in the width direction, the negative electrode active material layer 56 is not present on the negative electrode current collector foil 55, and the negative electrode current collector foil 55 is exposed. This exposed portion of the negative electrode current collector foil 55 protrudes in a spiral shape from the electrode laminate portion 50e to the other side DH2 in the electrode body axial direction DH in the electrode body axial direction DH, forming the aforementioned negative electrode current collector portion 50d. The negative electrode current collector portion 50d is connected to the negative electrode terminal 70.

[0034] Next, the intervening members 40, 45 will be described (see FIGS. 4, 3, and 2; protrusions are not shown in FIG. 2). The intervening members 40, 45 are made of metal (aluminum in the first embodiment) and are rectangular in shape when viewed from above. One intervening member 40 is interposed between the first main wall portion 11 of the case 10 and the electrode laminate portion 50e of the electrode body 50, and the other intervening member 45 is interposed between the second main wall portion 12 of the case 10 and the electrode laminate portion 50e of the electrode body 50. Note that these intervening members 40, 45 have the same configuration, and therefore will be described together below.

[0035] The interposing members 40, 45 protrude toward the inner side CH3 of the case thickness direction CH (toward the electrode stacking portion 50e of the electrode body 50) and have a plurality of convex portions (first bent convex rib portions 41, 46, second bent convex rib portions 42, 47, T-shaped convex rib portions 43, 48 and I-shaped convex rib portions 44, 49) that press the electrode stacking portion 50e in the electrode body thickness direction FH. Of these, a plurality of first bent ridges 41, 46 are provided on each of the interposition members 40, 45. When the battery 1 is placed in a position where the electrode body axial direction DH and the electrode body thickness direction FH of the electrode body 50 are parallel to the horizontal direction IH (the position of the battery 1 when in use), the first bent ridges 41, 46 are arranged on the inner side DH3 of the electrode body axial direction DH. in Lower AH2 Part of It extends from the upper side towards AH1, Next, the further up you go towards AH1, On the outer side DH4 of the electrode body axial direction DH To face The first bent ridges 41, 46 are elastically compressed by the first main wall 11 and the second main wall 12 of the case 10, and press the electrode laminate 50e of the electrode assembly 50 in the electrode assembly thickness direction FH, restricting the movement of the impregnating electrolyte 3a to the lower portions 50ega of the both end portions 50eg of the electrode laminate 50e in the electrode assembly axial direction DH, as shown by arrows P in Figures 4 and 5.

[0036] In addition, multiple second bent ridges 42, 47 are also provided on each of the interposition members 40, 45. When the battery 1 is placed in the above-mentioned posture during use, each of the second bent ridges 42, 47 is positioned inward in the axial direction DH3 Part of from First, the higher you go towards AH1,Axial direction outer side DH4 To face The second bent ridges 42, 47 are also elastically compressed by the first main wall 11 and the second main wall 12 of the case 10, and press the electrode stack 50e of the electrode assembly 50 in the electrode assembly thickness direction FH, restricting the impregnated electrolyte 3a from moving to the lower portions 50ega of the both end portions 50eg of the electrode stack 50e.

[0037] On the other hand, one T-shaped ridge 43, 48 is provided on each of the interposition members 40, 45. When the battery 1 is placed in its in-use position, the T-shaped ridge 43, 48 has a T-shaped configuration that extends from the lower side AH2 to the upper side AH1 at the inner axial side DH3 (specifically, at the center in the electrode body axial direction DH), branches out to the outer axial side DH4, bends, and further extends toward the outer axial side DH4. A plurality of I-shaped ridges 44, 49 are provided on each of the intervening members 40, 45. Each I-shaped ridge 44, 49 has an I-shape extending from an axially inner side DH3 toward an axially outer side DH4 near a lower portion 50ega of each of both end portions 50eg of the electrode stack 50e. In this way, in this embodiment 1, in addition to the first bent ridge portions 41, 46 and the second bent ridge portions 42, 47, T-shaped ridge portions 43, 48 and I-shaped ridge portions 44, 49 are provided, so that the entire electrode stack portion 50e of the electrode body 50 can be pressed more uniformly.

[0038] In the battery 1 of the first embodiment, the first main wall portion 11 and the second main wall portion 12 of the case 10 elastically compress the electrode laminate portion 50e of the electrode assembly 50 in the electrode assembly thickness direction FH. That is, the battery 1 is a self-compressing type in which the battery 1 itself elastically compresses the electrode laminate portion 50e of the electrode assembly 50. Therefore, when using the battery 1, it is not necessary to use a separate restraining member, or external restraint by a simple restraining member is sufficient. Furthermore, since the case 10 of the battery 1 is formed by joining a lid member 31 forming the first main wall portion 11 to a main body member 21 forming the second main wall portion 12 and four side wall portions 13 to 16, the self-compressing battery 1 can be easily manufactured as described below, and the battery 1 can be made inexpensively.

[0039] Incidentally, when the battery 1 is used in a position in which the electrode body axial direction DH and the electrode body thickness direction FH of the electrode body 50 are parallel to the horizontal direction IH, it has been found that the impregnated electrolyte 3a that flows out of the electrode body 50 from within the electrode body 50 to the outside of the electrode body 50 during charging and discharging moves as shown by arrows P in Figures 4 and 5, and tends to flow out from the lower parts 50ega of both end parts 50eg in the electrode body axial direction DH of the electrode stacked portion 50e. In contrast, the battery 1 is located on the inner side in the axial direction DH3 in Lower AH2 Part of It extends from the upper side towards AH1, Next, the more it goes towards the upper side AH1, the more it faces the outer side DH4 in the axial direction. Bending, Furthermore A plurality of first bent ridges 41, 46 extending toward the axially outer side DH4 and the axially inner side DH3 Part of from First, the more it goes towards the upper side AH1, the more it faces the outer side DH4 in the axial direction. Bending, Furthermore and a plurality of second bent ridge portions 42, 47 extending toward the outer side DH4 in the axial direction. These first bent ridge portions 41, 46 and second bent ridge portions 42, 47 each press against the electrode stack portion 50e of the electrode body 50, restricting the impregnated electrolyte 3a from moving to the lower portions 50ega of the both end portions 50eg of the electrode stack portion 50e.

[0040] Therefore, by pressing the electrode stack 50e of the electrode body 50 with the first bent ridge portions 41, 46 and the second bent ridge portions 42, 47, the impregnated electrolyte 3a in the electrode body 50 is less likely to move from the upper side AH1 to the lower side AH2 and from the axially inner side DH3 to the axially outer side DH4, and the impregnated electrolyte 3a can be prevented from moving to the lower parts 50ega of the both end parts 50eg of the electrode stack 50e. Therefore, as the battery 1 is used, the impregnated electrolyte 3a can be prevented from leaking out of the electrode body 50 through the lower parts 50ega of the both end parts 50eg of the electrode stack 50e.

[0041] Furthermore, in the first embodiment, an intervening member 40 is disposed between the first main wall portion 11 of the case 10 and the electrode laminate portion 50e of the electrode body 50, and an intervening member 45 is disposed between the second main wall portion 12 of the case 10 and the electrode laminate portion 50e of the electrode body 50, and these intervening members 40, 45 are provided with first bent ridge portions 41, 46 and second bent ridge portions 42, 47. Therefore, it is not necessary to provide bent ridge portions on the first main wall portion 11 or the second main wall portion 12 of the case 10.

[0042] Next, a method for manufacturing the battery 1 will be described (see FIGS. 6 to 9). A body member 21 to which a positive electrode terminal 60 and a negative electrode terminal 70 are fixed, and a lid member 31 are prepared in advance. A positive electrode plate 51, a negative electrode plate 54, and a pair of separators 57, each of which has a strip shape, are wound into a cylindrical shape around a winding axis DX, and then pressed flat to form an electrode assembly 50. The electrode assembly 50 is then wrapped in a bag-shaped insulating holder (not shown).

[0043] Then, in the "accommodating step S1" (see FIG. 6), the electrode assembly 50 wrapped in an insulating holder and the intervening members 40 and 45 are accommodated in the main body member 21 to which the positive terminal 60 and the negative terminal 70 are fixed, with the intervening members 40 and 45 stacked on the front and back of the electrode assembly 50 (see FIG. 7). Specifically, the main body member 21 is placed on a flat mounting table 510 of the pressing device 500 with the entire second main wall portion 12 abutting against the mounting table 510. Thereafter, the intervening member 45 is first accommodated in the main body member 21, and then the electrode assembly 50 is accommodated in an orientation such that the electrode assembly axial direction DH is parallel to the case width direction BH, the electrode assembly width direction EH is parallel to the case height direction AH, and the electrode assembly thickness direction FH is parallel to the case thickness direction CH, and the electrode laminate portion 50e of the electrode assembly 50 is stacked on the intervening member 45. Next, the interposition member 40 is placed on top of the electrode laminated portion 50e of the electrode body 50. After that, the positive electrode current collecting portion 50c of the electrode body 50 is connected to the positive electrode terminal 60 fixed to the main body member 21 by laser welding. Also, the negative electrode current collecting portion 50d of the electrode body 50 is connected to the negative electrode terminal 70 fixed to the main body member 21 by laser welding.

[0044] Next, in the "pressure compression step S2" (see FIG. 6), the lid member 31 is placed on the intervening member 45, the electrode assembly 50, and the intervening member 40 housed in the main body member 21, and an external force Fa is applied to the first main wall portion 11 formed by the lid member 31 and the second main wall portion 12 of the main body member 21 to press the intervening member 45, the electrode stack portion 50e of the electrode assembly 50, and the intervening member 40 in the electrode assembly thickness direction FH, thereby compressing the electrode stack portion 50e (see FIG. 8). Specifically, the pressing portion 520 of the pressing device 500 is brought into contact with the first main wall portion 11 formed by the lid member 31, and the lid member 31 and the main body member 21 are sandwiched between the pressing portion 520 and the mounting table 510, and the external force Fa is applied to the first main wall portion 11 and the second main wall portion 12. Then, the intervening member 45, the electrode stacking portion 50e of the electrode body 50, and the intervening member 40 are pressed in the thickness direction FH of the electrode body, compressing the electrode stacking portion 50e and abutting the lid peripheral portion 31f of the lid member 31 against the opening peripheral portion 21f of the opening 21c of the main body member 21 around the entire circumference (see Figure 9).

[0045] Next, in a "joining step S3" (see FIG. 6), the electrode body 50 is pressed and compressed by the pressing device 500, and the lid peripheral portion 31f of the lid member 31 is joined to the opening peripheral portion 21f of the body member 21 over the entire circumference, thereby forming the case 10 (see FIG. 9). In the present embodiment 1, the lid peripheral portion 31f and the opening peripheral portion 21f are irradiated with laser light LB to perform laser welding, thereby joining the lid peripheral portion 31f and the opening peripheral portion 21f over the entire circumference.

[0046] Next, in the "release step S4" (see FIG. 6), the external force Fa is released. That is, the pressing portion 520 of the pressing device 500 is moved away from the lid member 31 to release the external force Fa. At this time, because the case 10 has already been formed in the joining step S3, the compressed electrode stack portion 50e does not return to its original state (thickness). After the external force Fa is released, the electrode stack portion 50e is elastically compressed by the first main wall portion 11 and the second main wall portion 12 of the case 10.

[0047] Next, in the "pouring and sealing step S5," the electrolyte 3 is poured into the case 10 through the pouring hole 13k, and the electrolyte 3 is impregnated into the electrode body 50. Thereafter, the pouring hole 13k is covered from the outside with a sealing member 18, and the sealing member 18 is laser-welded to the case 10 to hermetically seal the gap between the sealing member 18 and the case 10. Next, in the "initial charging and aging step S6," a charging device (not shown) is connected to the battery 1, and the battery 1 is initially charged. After that, the initially charged battery 1 is left to stand for a predetermined time to age the battery 1. In this way, the battery 1 is completed.

[0048] In a conventional prismatic battery, the case 10 is configured by a bottomed, square-tubular body member that forms the first main wall 11, the second main wall 12, and three side walls (the second side wall 14, the third side wall 15, and the fourth side wall 16) of the case 10, and a lid member that forms the first side wall 13. It is difficult to manufacture a self-compressing battery with this type of configuration. This is because the gap between the first main wall 11 and the second main wall 12 of the body member is narrower than the combined thickness of the electrode body 50 and the intervening members 40, 45 in order to press and compress the electrode stack 50e of the electrode body 50 in the assembled battery, making it difficult to insert the electrode body 50 and the intervening members 40, 45 into the body member.

[0049] In contrast, in the manufacturing method of the battery 1 described above, in the housing step S1, the electrode assembly 50 and the intervening members 40, 45 are housed in the main body member 21, which is a bottomed square tube that forms the second main wall portion 12 and the four side wall portions 13 to 16, so that the electrode assembly 50 and the intervening members 40, 45 can be easily housed in the main body member 21. Then, by performing the pressing and compressing step S2, the joining step S3, and the releasing step S4 thereafter, a self-compressing battery 1 can be easily manufactured in which the battery 1 itself elastically compresses the electrode stack portion 50e of the electrode assembly 50. Furthermore, in this embodiment 1, the battery 1 is manufactured using the intervening members 40, 45, so that the battery 1 can be manufactured in which the electrode stack portion 50e of the electrode body 50 is appropriately pressed by the first bent ridge portions 41, 46 and the second bent ridge portions 42, 47 of the intervening members 40, 45.

[0050] (Embodiment 2) Next, a second embodiment will be described (see FIGS. 10 and 11). Descriptions of parts similar to those of the first embodiment will be omitted or simplified. In the battery 1 of the first embodiment, intervening members 40, 45 are disposed between the first main wall portion 11 and the second main wall portion 12 of the case 10 and the electrode stacking portion 50e of the electrode body 50. In contrast, in the battery (electricity storage device) 100 of the second embodiment, no intervening member is disposed between the first main wall portion 111 and the second main wall portion 112 of the case 110 and the electrode stack portion 50e of the electrode body 50. Furthermore, in the second embodiment, the shape of the case 110 differs from that of the case 10 of the first embodiment, and convex portions (first bent convex ridge portions 141, 146, second bent convex ridge portions 142, 147, T-shaped convex ridge portions 143, 148, and I-shaped convex ridge portions 144, 149) are provided on the first main wall portion 111 and the second main wall portion 12 of the case 110, respectively.

[0051] Specifically, the first main wall portion 111 of the case 110 of the second embodiment has a rectangular central portion 111e in plan view, excluding its peripheral portion 111s, which protrudes toward the inner side CH3 in the case thickness direction CH (toward the electrode laminated portion 50e). This central portion 111e is provided with a plurality of protrusions (first bent ridge portions 141, second bent ridge portions 142, T-shaped ridge portions 143, and I-shaped ridge portions 144) that protrude toward the inner side CH3 in the case thickness direction CH and press the electrode laminated portion 50e of the electrode assembly 50 in the electrode assembly thickness direction FH. These convex portions (first bent convex rib portion 141, second bent convex rib portion 142, T-shaped convex rib portion 143 and I-shaped convex rib portion 144) have the same shape and function as the convex portions (first bent convex rib portion 41, second bent convex rib portion 42, T-shaped convex rib portion 43 and I-shaped convex rib portion 44) provided on the intervening member 40 of embodiment 1.

[0052] Furthermore, the second main wall portion 112 of the case 110 of the second embodiment has a central portion 112e, which is rectangular in plan view, excluding its peripheral portion 112s, that protrudes toward the inner side CH3 in the case thickness direction CH (toward the electrode laminated portion 50e). This central portion 112e is provided with a plurality of protrusions (a first bent ridge portion 146, a second bent ridge portion 147, a T-shaped ridge portion 148, and an I-shaped ridge portion 149) that protrude toward the inner side CH3 in the case thickness direction CH and press the electrode laminated portion 50e of the electrode assembly 50 in the electrode assembly thickness direction FH. These convex portions (first bent convex rib portion 146, second bent convex rib portion 147, T-shaped convex rib portion 148 and I-shaped convex rib portion 149) have the same shape and function as the convex portions (first bent convex rib portion 46, second bent convex rib portion 47, T-shaped convex rib portion 48 and I-shaped convex rib portion 49) provided on the intervening member 45 of embodiment 1.

[0053] In the battery 100 of the second embodiment, the first main wall portion 111 and the second main wall portion 112 of the case 110 also elastically compress the electrode stack portion 50e of the electrode assembly 50 in the electrode assembly thickness direction FH. That is, this battery 100 is a self-compressing type in which the battery 100 itself elastically compresses the electrode stack portion 50e of the electrode assembly 50. Therefore, when using the battery 100, it is not necessary to use a separate restraining member, or external restraint by a simple restraining member is sufficient. Furthermore, because the case 110 is formed by joining the lid member 131 forming the first main wall portion 111 to the main body member 121 forming the second main wall portion 112 and the four side walls 13 to 16, the self-compressing battery 100 can be easily manufactured and can be made inexpensively.

[0054] The battery 100 also has first bent ridge portions 141, 146 and second bent ridge portions 142, 147. By pressing the electrode stack portion 50e of the electrode assembly 50 with these first bent ridge portions 141, 146 and second bent ridge portions 142, 147, the impregnated electrolyte 3a in the electrode assembly 50 is less likely to move from the upper side AH1 to the lower side AH2 and from the axially inner side DH3 to the axially outer side DH4, thereby preventing the impregnated electrolyte 3a from moving to the lower parts 50ega of the both end portions 50eg of the electrode stack portion 50e. Therefore, as the battery 100 is used, the impregnated electrolyte 3a can be prevented from leaking out of the electrode assembly 50 through the lower parts 50ega of the both end portions 50eg of the electrode stack portion 50e.

[0055] Furthermore, in the second embodiment, first bent ridge portions 141, 146 and second bent ridge portions 142, 147 are provided on the first main wall portion 111 and the second main wall portion 112 of the case 110. Therefore, no intervening member having a bent ridge portion is disposed between the first main wall portion 111 or the second main wall portion 112 of the case 110 and the electrode body 50, and the number of parts is reduced.

[0056] Next, a manufacturing method of the battery 100 of the second embodiment will be described. First, in the accommodation step S1, the electrode assembly 50 wrapped in an insulating holder is accommodated in a main body member 121 to which a positive terminal 60 and a negative terminal 70 are fixed. In the second embodiment, no intervening member is disposed. Thereafter, as in the first embodiment, the positive electrode current collecting portion 50c and the negative electrode current collecting portion 50d of the electrode assembly 50 are laser-welded to the positive electrode terminal 60 and the negative electrode terminal 70 fixed to the main body member 121, respectively.

[0057] Next, in the pressing and compressing step S2, the lid member 131 is placed on the electrode assembly 50 housed in the main body member 121, and an external force Fa is applied to the first main wall portion 111 formed by the lid member 131 and the second main wall portion 112 of the main body member 121 to press and compress the electrode stack portion 50e of the electrode assembly 50 in the electrode assembly thickness direction FH. In this case, in the second embodiment, the electrode stack portion 50e is pressed in the electrode assembly thickness direction FH by the first bent ridge portions 141, 146, the second bent ridge portions 142, 147, the T-shaped ridge portions 143, 148, and the I-shaped ridge portions 144, 149 provided on the case 110. Then, the lid peripheral portion 131f of the lid member 131 is brought into contact with the opening peripheral portion 121f of the opening 121c of the main body member 121 along the entire circumference. This step is carried out using the same pressing device 500 (see FIG. 9) as in the first embodiment.

[0058] Next, in the joining step S3, as in the first embodiment, the lid peripheral portion 131f of the lid member 131 is laser-welded to the opening peripheral portion 121f of the body member 121 along the entire periphery to form the case 110. Thereafter, as in the first embodiment, the releasing step S4, the liquid injection and sealing step S5, and the initial charging and aging step S6 are performed to complete the battery 100.

[0059] In the manufacturing method of the battery 100 of the second embodiment, in the housing step S1, the electrode body 50 is housed in a bottomed, square-tubular body member 121 that forms the second main wall portion 112 and four side wall portions 13 to 16, so that the electrode body 50 can be easily housed in the body member 121. Then, by performing the pressing and compressing step S2, the joining step S3, and the releasing step S4, the self-compressing battery 100 can be easily manufactured. In particular, in the second embodiment, an intervening member having a bent ridge portion is not disposed in the body member 121, so that the housing step S1 and the pressing and compressing step S2 can be easily carried out. Other parts similar to those of the first embodiment provide the same functions and effects as those of the first embodiment.

[0060] The present invention has been described above in accordance with embodiments 1 and 2, but it goes without saying that the present invention is not limited to embodiments 1 and 2, and can be modified and applied as appropriate within the scope of the gist of the present invention. For example, in embodiment 1, intervening members 40, 45 having curved ridge portions 41, 42, 46, 47 are arranged between the first main wall portion 11 of the case 10 and the electrode body 50, and between the second main wall portion 12 of the case 10 and the electrode body 50, respectively, but an intervening member having a curved ridge portion may be arranged only between either one of them. In addition, in embodiment 2, the first main wall portion 111 and the second main wall portion 112 of the case 110 are provided with the curved ridge portions 141, 142, 146, and 147, respectively, but the curved ridge portions may be provided on only one of the first main wall portion 111 and the second main wall portion 112. [Explanation of symbols]

[0061] 1,100 batteries (energy storage devices) 3a Impregnating electrolyte 10,110 cases 11,111 1st main wall 12,112 2nd main wall 13 First side wall portion (upper wall portion) 14 Second side wall (lower wall) 15 Third side wall 16 Fourth side wall 21,121 Body parts 21c,121c opening 21f, 121f Opening edge 31,131 Cover member 31f, 131f Lid edge 40,45 Intervening member 41,46,141,146 1st bent protrusion 42,47,142,147 2nd bent protrusion 50 Electrode body 50e Electrode stacking section 50eg (electrode stack) end 50ega (bottom) 51 Positive electrode plate 54 Negative electrode plate 57 Separator AH Case height direction AH1 upper side AH2 lower side CH Case thickness direction CH3 Inner side in thickness direction DH Electrode body axis direction DH3 Axial inside DH4 Axial outside FH Electrode body thickness direction IH horizontal direction Fa External Force S1 Storage process S2 Press compression process S3 Joining process S4 release process

Claims

1. Case and an electrode assembly housed in the case; an impregnating electrolyte impregnated in the electrode body, the case has a rectangular box shape and includes a rectangular first main wall portion, a rectangular second main wall portion facing the first main wall portion, and four rectangular side wall portions connecting the first main wall portion and the second main wall portion and extending in the case thickness direction; The electrode body is The battery is a flat wound type battery in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound flatly with a pair of strip-shaped separators interposed therebetween, a rectangular parallelepiped electrode stack portion in which the positive electrode plate, the negative electrode plate, and the separator are stacked in a flat plate shape in the thickness direction of the electrode body, The electrode body is housed in the case in a position where the thickness direction of the electrode body is parallel to the thickness direction of the case. An electricity storage device, The above case is a main body member having a rectangular cylindrical shape with a bottom, the main body member forming the second main wall portion and the four side wall portions and having a rectangular opening formed by the four side wall portions; a rectangular lid member that forms the first main wall portion and has a lid peripheral portion joined to an opening peripheral portion of the opening of the main body member along the entire periphery, the first main wall portion and the second main wall portion of the case elastically compress the electrode laminate portion of the electrode body in the thickness direction of the electrode body, A plurality of bent ridges protruding inward in the thickness direction of the case in the thickness direction of the case, When the electricity storage device is placed in a position where the electrode body axial direction and the electrode body thickness direction are parallel to the horizontal direction, A form in which the electrode body extends from a lower portion on the inner side in the axial direction of the electrode body axial line toward the upper side, then bends so as to face outward in the axial direction of the electrode body axial line as it moves upward, and further extends outward in the axial direction; and / or The shaft has a shape that first bends upward from an inner portion in the axial direction so as to face outward in the axial direction, and then further extends outward in the axial direction, The electrode laminated portion of the electrode body is pressed in the thickness direction of the electrode body by elastic compression by the first main wall portion and the second main wall portion, thereby restricting the impregnated electrolyte from moving to the lower portions of both end portions of the electrode laminated portion in the axial direction of the electrode body. Having multiple bent ridges Energy storage device.

2. The electricity storage device according to claim 1 , an intervening member is provided between the first main wall portion of the case and the electrode stack portion of the electrode body, and / or between the second main wall portion of the case and the electrode stack portion of the electrode body; The plurality of bent ridges are provided on the interposing member. Energy storage device.

3. The electricity storage device according to claim 1 , The plurality of bent ridges are provided on at least one of the first main wall portion and the second main wall portion of the case. Energy storage device.

4. Case and an electrode assembly housed in the case; an impregnating electrolyte impregnated in the electrode body, the case has a rectangular box shape and includes a rectangular first main wall portion, a rectangular second main wall portion facing the first main wall portion, and four rectangular side wall portions connecting the first main wall portion and the second main wall portion and extending in the case thickness direction; The electrode body is The battery is a flat wound type battery in which a strip-shaped positive electrode plate and a strip-shaped negative electrode plate are wound flatly with a pair of strip-shaped separators interposed therebetween, a rectangular parallelepiped electrode stack portion in which the positive electrode plate, the negative electrode plate, and the separator are stacked in a flat plate shape in the thickness direction of the electrode body, The electrode body is housed in the case in a position where the thickness direction of the electrode body is parallel to the thickness direction of the case. An electricity storage device, The above case is a main body member having a rectangular cylindrical shape with a bottom, the main body member forming the second main wall portion and the four side wall portions and having a rectangular opening formed by the four side wall portions; a rectangular lid member that forms the first main wall portion and has a lid peripheral portion joined to an opening peripheral portion of the opening of the main body member along the entire periphery, the first main wall portion and the second main wall portion of the case elastically compress the electrode laminate portion of the electrode body in the thickness direction of the electrode body, A plurality of bent ridges protruding inward in the thickness direction of the case in the thickness direction of the case, When the electricity storage device is placed in a position where the electrode body axial direction and the electrode body thickness direction are parallel to the horizontal direction, A form in which the electrode body extends from a lower portion on the inner side in the axial direction of the electrode body axial line toward the upper side, then bends so as to face outward in the axial direction of the electrode body axial line as it moves upward, and further extends outward in the axial direction; and / or The shaft has a shape that first bends upward from an inner portion in the axial direction so as to face outward in the axial direction, and then further extends outward in the axial direction, The electrode laminated portion of the electrode body is pressed in the thickness direction of the electrode body by elastic compression by the first main wall portion and the second main wall portion, thereby restricting the impregnated electrolyte from moving to the lower portions of both end portions of the electrode laminated portion in the axial direction of the electrode body. Having multiple bent ridges A method for manufacturing an electricity storage device, comprising: a housing step of housing the electrode body in the main body member; a pressing and compressing step of placing the lid member on the electrode body accommodated in the main body member, and applying an external force to the first main wall portion formed by the lid member and the second main wall portion of the main body member to press and compress the electrode laminate portion of the electrode body in the thickness direction of the electrode body; a joining step of joining the lid peripheral portion of the lid member to the opening peripheral portion of the opening of the main body member along the entire periphery while pressing and compressing the electrode body, thereby forming the case; and a release step of releasing the external force after the joining step. A method for manufacturing an electricity storage device.

5. A method for manufacturing the electricity storage device according to claim 4, The electricity storage device is an intervening member is provided between the first main wall portion of the case and the electrode stack portion of the electrode body, and / or between the second main wall portion of the case and the electrode stack portion of the electrode body; the plurality of bent ridge portions are provided on the interposition member, The containing step includes: The electrode body and the interposing member are accommodated in the main body member with the interposing member overlapping the electrode stacking portion of the electrode body; The pressing and compressing step The electrode laminated portion and the interposed member of the electrode body are pressed in the thickness direction of the electrode body. A method for manufacturing an electricity storage device.

6. A method for manufacturing the electricity storage device according to claim 4, the plurality of bent ridge portions are provided on at least one of the first main wall portion and the second main wall portion of the case, The pressing and compressing step The bent ridge portion provided on the case presses the electrode laminate portion of the electrode body in the thickness direction of the electrode body. A method for manufacturing an electricity storage device.

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