Electricity storage device and method for manufacturing the same

Abstract

To provide a power storage device which can elastically compress an electrode body in the thickness direction of the electrode body by the power storage device.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 first main wall part 11 and the second main wall part 12 elastically compressing an electrode laminate unit 50. The case includes: laminate part pressing units 41, 46 for pressing an electrode laminate unit 50e of the electrode body 50 in a thickness direction FH of the electrode body; and R-part pressing units 42A, 42B, 47A, and 47B for pressing electrode R-parts 50rA and 50rB of the electrode body 50 in a thickness direction FH of the electrode body.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.

[0005] The present invention has been made in view of the above-described circumstances, and provides an electricity storage device in which an electrode body is elastically compressed in the thickness direction of the electrode body by the electricity storage device itself, 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 includes a case and an electrode assembly housed in the case, the case being shaped like a rectangular parallelepiped box and having 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 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 electrode assembly having a pair of electrode R portions in which the positive electrode plate, the negative electrode plate, and the separator are overlapped while being bent into a semi-cylindrical shape, and a rectangular parallelepiped electrode stack portion located between the pair of electrode R portions and 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 assembly, the electrode assembly being shaped like a rectangular parallelepiped 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 assembly, the electrode assembly being shaped like a rectangular parallelepiped in which the thickness direction of the electrode assembly is parallel to the thickness direction of the case, The case is an electricity storage device housed in a case, the case having a bottomed, square cylindrical main body member that forms the second main wall portion and four side wall portions and has a rectangular opening formed 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 around the entire circumference to the opening peripheral portion of the opening of the main body member, the first main wall portion and the second main wall portion of the case elastically compressing the electrode body in the thickness direction of the electrode body, the case having a stack portion pressing portion that presses the electrode stack portion of the electrode body in the thickness direction of the electrode body by elastic compression by the first main wall portion and the second main wall portion, and an R portion pressing portion that presses the electrode R portion of the electrode body in the thickness direction of the electrode body by elastic compression by the first main wall portion and the second main wall portion.

[0007] In the above-described electricity storage device, the electrode body is elastically compressed in the thickness direction of the electrode body by the first main wall portion and the second main wall portion of the case. That is, this electricity storage device is a self-compressing type in which 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. The above-mentioned electricity storage device also has a laminated portion pressing portion that presses the electrode laminated portion of the electrode assembly, and an R portion pressing portion that presses the electrode R portion of the electrode assembly. Therefore, since the electrode R portion of the electrode assembly can be pressed in addition to the electrode laminated portion of the electrode assembly, the electrode assembly can be pressed over a wider area. This improves the charge / discharge cycle characteristics of the electricity storage device.

[0008] 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 "R portion pressing portion" includes a first R portion pressing portion that presses one electrode R portion (first electrode R portion) of a pair of electrode R portions, and a second R portion pressing portion that presses the other electrode R portion (second electrode R portion). In the present invention, it is sufficient to have at least one of the first R portion pressing portion and the second R portion pressing portion, but it is more preferable to have both.

[0009] The "stack portion pressing portion" and the "R portion pressing portion" can be provided on at least one of the first main wall portion and the second main wall portion of the case. Specifically, examples include providing the stack portion pressing portion and the R portion pressing portion on both the first main wall portion and the second main wall portion, providing the stack portion pressing portion and the R portion pressing portion only on the first main wall portion, providing the stack portion pressing portion and the R portion pressing portion only on the second main wall portion, providing the stack portion pressing portion on the first main wall portion and the R portion pressing portion on the second main wall portion, and providing the R portion pressing portion on the first main wall portion and the stack portion pressing portion on the second main wall portion.

[0010] Alternatively, the laminated portion pressing portion and the R portion pressing portion may be separate members from the case. That is, an intervening member may be disposed between the first main wall portion of the case and the electrode body, or between the second main wall portion of the case and the electrode body, and the laminated portion pressing portion and the R portion pressing portion may be provided on this intervening member. Specifically, for example, an intervening member is placed between the first main wall portion and the electrode body, and a laminated portion pressing portion and an R portion pressing portion are provided on this intervening member, or an intervening member is placed between the second main wall portion and the electrode body, and a laminated portion pressing portion and an R portion pressing portion are provided on this intervening member. Other examples include a configuration in which a first intervening member is placed between the first main wall portion and the electrode body, and a second intervening member is placed between the second main wall portion and the electrode body, and a laminated portion pressing portion and an R portion pressing portion are provided on both the first intervening member and the second intervening member, respectively, or a configuration in which only a laminated portion pressing portion is provided on one intervening member and only an R portion pressing portion is provided on the other intervening member. Another possible configuration is to place an intervening member between the first main wall portion and the electrode laminate portion, provide only the laminate portion pressing portion on this intervening member, and provide only the R portion pressing portion on the second main wall portion of the case.

[0011] (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 body and between the second main wall portion of the case and the electrode body, and the R-portion pressing portion is preferably provided on the intervening member.

[0012] In the above-described electricity storage device, an intervening member is disposed between the first main wall portion of the case and the electrode body or between the second main wall portion of the case and the electrode body, and the intervening member is provided with the aforementioned R-portion pressing portion. Therefore, when an intervening member having an R-portion pressing portion is disposed between the first main wall portion and the electrode body, it is not necessary to provide an R-portion pressing portion on the first main wall portion. Furthermore, when an intervening member having an R-portion pressing portion is disposed between the second main wall portion and the electrode body, it is not necessary to provide an R-portion pressing portion on the second main wall portion.

[0013] The "intervening member" may be an intervening member in which only a part of the intervening member forms the R-portion pressing portion, or an intervening member in which the entire intervening member forms the R-portion pressing portion. The laminated portion pressing portion may be provided on the first or second main wall of the case, or an intervening member may be disposed between the first or second main wall of the case and the electrode body, and the laminated portion pressing portion may be provided on this intervening member. Note that the intervening member provided on the laminated portion pressing portion and the intervening member provided on the R portion pressing portion may be the same intervening member or different intervening members.

[0014] (3) Furthermore, in the electricity storage device according to (1), the R-portion pressing portion may be provided on at least one of the first main wall portion and the second main wall portion of the case.

[0015] In the above-described electricity storage device, the R-portion pressing portion is provided on at least one of the first main wall portion and the second main wall portion of the case. Therefore, when the R-portion pressing portion is provided on the first main wall portion, there is no need to place an intervening member having the R-portion pressing portion between the first main wall portion and the electrode body. Furthermore, when the R-portion pressing portion is provided on the second main wall portion, there is no need to place an intervening member having the R-portion pressing portion between the second main wall portion and the electrode body.

[0016] Specific examples of the R-portion pressing portion provided on at least one of the first main wall portion and the second main wall portion include a first R-portion pressing portion that presses the first electrode R portion and a second R-portion pressing portion that presses the second electrode R portion provided only on the first main wall portion; a first R-portion pressing portion and a second R-portion pressing portion provided only on the second main wall portion; a first R-portion pressing portion and a second R-portion pressing portion provided on both the first and second main wall portions; a first R-portion pressing portion provided only on the first main wall portion and a second R-portion pressing portion provided only on the second main wall portion; a first R-portion pressing portion provided only on the first main wall portion or only on the second main wall portion; or a second R-portion pressing portion provided only on the first or second main wall portion. The aforementioned stacked portion pressing portion may be provided on the first main wall portion or the second main wall portion of the case, or an intervening member may be placed between the first main wall portion or the second main wall portion of the case and the electrode body, and the stacked portion pressing portion may be provided on this intervening member.

[0017] (4) The energy storage device according to any one of (1) to (3) may further include an intervening member between the first main wall portion of the case and the electrode body, and between the second main wall portion of the case and the electrode body, and the stack pressing portion may be provided on the intervening member.

[0018] In the above-described electricity storage device, an intervening member is disposed between at least one of the first main wall portion of the case and the electrode body and the second main wall portion of the case and the electrode body, and the intervening member is provided with the aforementioned stack portion pressing portion. Therefore, when an intervening member having a stack portion pressing portion is disposed between the first main wall portion and the electrode body, it is not necessary to provide a stack portion pressing portion on the first main wall portion. Also, when an intervening member having a stack portion pressing portion is disposed between the second main wall portion and the electrode body, it is not necessary to provide a stack portion pressing portion on the second main wall portion.

[0019] The "intervening member" may be an intervening member in which only a part of the intervening member forms the laminated portion pressing portion, or an intervening member in which the entire intervening member forms the laminated portion pressing portion.

[0020] (5) In the electricity storage device according to any one of (1) to (3), the stacked portion pressing portion may be provided on at least one of the first main wall portion and the second main wall portion of the case.

[0021] In the above-described electricity storage device, the stack portion pressing portion is provided on at least one of the first main wall portion and the second main wall portion of the case. Therefore, when the stack portion pressing portion is provided on the first main wall portion, there is no need to place an intervening member having the stack portion pressing portion between the first main wall portion and the electrode body. Furthermore, when the stack portion pressing portion is provided on the second main wall portion, there is no need to place an intervening member having the stack portion pressing portion between the second main wall portion and the electrode body.

[0022] (6) Preferably, the electricity storage device according to any one of (1) to (5) further comprises the R portion pressing portion, which is located on one side of the electrode R portion in the thickness direction of the electrode body, and which presses the electrode R portion toward the other side in the thickness direction of the electrode body, and the R portion pressing portion is located on the other side of the electrode R portion in the thickness direction of the electrode body, and which presses the electrode R portion toward one side in the thickness direction of the electrode body, and the R portion pressing portion is located on the other side of the electrode R portion in the thickness direction of the electrode body, and the electrode R portion is sandwiched and pressed in the thickness direction of the electrode body by the one side R portion pressing portion and the other side R portion pressing portion.

[0023] Because the electrode R portion is semi-cylindrical, it is more difficult to press the electrode R portion in the thickness direction of the electrode body than to press the rectangular parallelepiped electrode laminate portion in the thickness direction of the electrode body. In contrast, in the above-mentioned energy storage device, the electrode R portion is sandwiched and pressed in the thickness direction of the electrode body between the R portion pressing portion on one side and the R portion pressing portion on the other side. This allows the electrode R portion to be pressed more appropriately.

[0024] (7) Yet another aspect is a battery comprising a case and an electrode assembly housed in the case, the case being shaped like a rectangular parallelepiped box and having 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 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, and the positive electrode plate, the negative electrode plate, and the separator are bent into a semi-cylindrical shape and overlapped to form a pair of electrodes. and a rectangular parallelepiped electrode laminated portion located between the pair of electrode R portions, in which the positive electrode plate, the negative electrode plate, and the separator are laminated in a flat plate shape in the thickness direction of the electrode body, and the case is accommodated in the case with the thickness direction of the electrode body parallel to the thickness direction of the case, and the case comprises a bottomed square cylindrical main body member that forms the second main wall portion and the four side wall portions and has a rectangular opening formed by the four side wall portions, and a rectangular cover that forms the first main wall portion and has a lid peripheral portion joined around the entire periphery to the opening peripheral portion of the opening of the main body member. a cover member, wherein the electrode body is elastically compressed in a thickness direction of the electrode body by the first main wall portion and the second main wall portion of the case, and a laminated portion pressing portion that presses the electrode laminated portion of the electrode body in the thickness direction of the electrode body by elastic compression by the first main wall portion and the second main wall portion, and an R portion pressing portion that presses the electrode R portion of the electrode body in the thickness direction of the electrode body by elastic compression by the first main wall portion and the second main wall portion, The method for manufacturing an electricity storage device includes: an accommodation step; 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 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 around the entire circumference while the electrode body is pressed and compressed, thereby forming the case; and a release step of releasing the external force after the joining step.

[0025] 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 body in the assembled battery. This makes it difficult to insert the electrode body, etc., into the body member.

[0026] In contrast, in the manufacturing method of the above-mentioned electricity storage device, in the housing step, the electrode body is first housed in a bottomed, square-tubular main body member that forms a second main wall portion and four side walls, so that the electrode body 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 body is elastically compressed by the electricity storage device itself.

[0027] 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.

[0028] (8) Further, in the method for manufacturing an electric storage device described in (7), the electric storage device may include an intervening member forming the R-portion pressing portion between at least one of the first main wall portion of the case and the electrode body and the second main wall portion of the case and the electrode body, the accommodating step may include accommodating the electrode body and the intervening member by stacking the intervening member on the electrode body, and the pressing and compressing step may include pressing the electrode body and the intervening member in the thickness direction of the electrode body.

[0029] 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 it is possible to manufacture an electricity storage device in which the electrode R portion of the electrode assembly is appropriately pressed by the R portion pressing portion of the intervening member.

[0030] (9) Furthermore, in the method for manufacturing an electric storage device described in (7), the R portion pressing portion 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 R portion pressing portion provided on the case presses the electrode R portion of the electrode body in the thickness direction of the electrode body.

[0031] In the above-described method for manufacturing an electricity storage device, the insertion step and the pressing and compressing step can be easily performed by not disposing an intervening member that forms the round portion pressing portion.

[0032] (10) The method for manufacturing an electric storage device according to any one of (7) to (9), further comprising the step of: providing the laminated portion pressing portion between the first main wall portion of the case and the electrode body, and between the second main wall portion of the case and the electrode body. Susuke The method for manufacturing an electricity storage device may include a step of stacking the intervening member on the electrode body in the accommodating step, and the step of pressing the electrode body and the intervening member in the thickness direction of the electrode body in the pressing and compressing step.

[0033] 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 electrode laminated portion of the electrode body is appropriately pressed by the laminated portion pressing portion of the intervening member.

[0034] (11) Further, in the method for manufacturing an electric storage device according to any one of (7) to (9), the stack pressing portion 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 electrode stack portion of the electrode body is pressed in the thickness direction of the electrode body by the stack pressing portion provided on the case.

[0035] In the above-described method for manufacturing an electricity storage device, the accommodation step and the press-compression step can be easily performed by not disposing an intervening member that forms the laminated portion pressing portion.

[0036] (12) Further, in the method for manufacturing an electricity storage device according to any one of (7) to (11), the electricity storage device may include the R portion pressing portion, which is located on one side of the electrode R portion in the thickness direction of the electrode body, and which presses the electrode R portion toward the other side in the thickness direction of the electrode body, and the R portion pressing portion, which is located on the other side of the electrode R portion in the thickness direction of the electrode body, and which presses the electrode R portion toward one side in the thickness direction of the electrode body, and the one-side R portion pressing portion and the other-side R portion pressing portion sandwich the electrode R portion in the thickness direction of the electrode body, and the pressing and compressing step may be a method for manufacturing an electricity storage device in which the one-side R portion pressing portion and the other-side R portion pressing portion sandwich the electrode R portion in the thickness direction of the electrode body.

[0037] In the manufacturing method of the above-described electricity storage device, the electrode R portion is sandwiched and pressed in the thickness direction of the electrode body between the one-side R portion pressing portion and the other-side R portion pressing portion, so that an electricity storage device in which the electrode R portion is pressed more appropriately can be manufactured. [Brief explanation of the drawings]

[0038] [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] 6 is a cross-sectional view taken along the arrows AA in FIGS. 1, 4, and 5, along the case width direction and case thickness direction of the battery according to the first embodiment. FIG. [Figure 4] 1, 3, and 5 along the case height direction and case thickness direction of the battery according to the first embodiment. [Figure 5] 1 is a plan view of the battery according to Embodiment 1, seen from the inner side in the thickness direction of a first intervening member (second intervening member). FIG. [Figure 6] FIG. 1 is a perspective view of an electrode assembly according to a first embodiment. [Figure 7] 2 is a flowchart of a method for manufacturing a battery according to the first embodiment. [Figure 8]4 is an explanatory view showing a state in which the electrode assembly, the first intervening member, and the second intervening member are accommodated in the main body member in an accommodating step in the manufacturing method of the battery according to the first embodiment. FIG. [Figure 9] 4 is an explanatory view showing how an external force is applied to press the electrode assembly, the first intervening member, and the second intervening member in the thickness direction of the electrode assembly in a press-compression step in the manufacturing method for the battery according to the first embodiment. FIG. [Figure 10] 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 11] 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 12] 5 is a cross-sectional view corresponding to FIG. 4, taken along the case height direction and case thickness direction of the battery according to Embodiment 2. FIG. [Figure 13] 10 is a plan view of the battery according to Embodiment 2, seen from the inside in the thickness direction of the first main wall portion (second main wall portion) of the case. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0039] (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 (electricity storage device) 1 according to this first embodiment, FIG. 2 shows an exploded perspective view of the battery 1, and FIGS. 3 and 4 show cross-sectional views of the battery 1. FIG. 5 shows a plan view of the battery 1 as seen from the inner side CH3 in the thickness direction of the first intervening member 40 (second intervening member 45). FIG. 6 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 6. The battery 1 is a rectangular (rectangular) sealed lithium ion secondary battery that can be installed in vehicles such as hybrid cars, plug-in hybrid cars, and electric cars.

[0040] 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. A first intervening member 40 and a second intervening member 45 are also housed within the case 10, overlapping the electrode assembly 50 (see FIGS. 2 to 5, not shown in FIG. 1). An electrolyte 3 is also housed within the case 10, a portion of which is impregnated within the electrode assembly 50 and the remainder of which is pooled on the second side wall 14, which is the lower wall of the case 10.

[0041] 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 FIGS. 3 and 4), 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 FIGS. 3 and 4).

[0042] 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.

[0043] A safety valve 17 is provided on first side wall 13, which is also the top wall of case 10, and breaks to open when the internal pressure of case 10 exceeds the valve opening pressure. Also provided on first side wall 13 is a 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 portion on one side BH1 in the case width direction BH (see FIGS. 1 and 2, not shown in FIGS. 3 and 4). 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 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 within the case 10, and also extends through the first side wall 13 to the outside of the battery.

[0044] 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 (see FIGS. 1 and 2, not shown in FIGS. 3 and 4). 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 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 within the case 10, and also extends through the first side wall 13 to the outside of the battery.

[0045] 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.

[0046] Next, the electrode assembly 50 will be described (see FIGS. 1 to 4 and 6). This electrode assembly 50 is formed by stacking a strip-shaped positive electrode plate (electrode plate) 51 and a strip-shaped negative electrode plate (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 (a first electrode R portion 50rA and a second electrode R portion 50rB) located at both ends of the electrode assembly in the width direction EH, and an electrode laminate portion 50e located therebetween. The first electrode R portion 50rA and the second electrode R portion 50rB are semi-cylindrical portions in which the positive electrode plate 51, the negative electrode plate 54, and the separator 57 are bent into a semi-cylindrical shape and overlapped. On the other hand, the electrode stack portion 50e is a rectangular parallelepiped portion in which the positive electrode plates 51, the negative electrode plates 54, and the separators 57 are stacked in the electrode body thickness direction FH like flat plates. Furthermore, the electrode body 50 has a positive electrode current collector 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 collector 50d (described later) at an end on the other side DH2 in the electrode body axial direction DH.

[0047] 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 in a state 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 assembly 50 in the electrode assembly thickness direction FH.

[0048] 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.

[0049] 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.

[0050] Next, the first intervening member 40 and the second intervening member 45 will be described (see FIGS. 2 to 5; the pressing portion is not shown in FIG. 2). The first intervening member 40 and the second intervening member 45 are made of metal (aluminum in the first embodiment) and have a rectangular shape in a plan view. The first intervening member 40 is intervened between the first main wall portion 11 of the case 10 and the electrode body 50, and the second intervening member 45 is intervened between the second main wall portion 12 of the case 10 and the electrode body 50.

[0051] The first intervening member 40 consists of a one-side laminated portion pressing portion (laminated portion pressing portion) 41, a one-side first R portion pressing portion (R portion pressing portion) 42A, a one-side second R portion pressing portion (R portion pressing portion) 42B, and a plate-shaped base 43 that forms the portion other than these pressing portions. Of these, the one-side laminated portion pressing portion 41 has a rectangular shape in a plan view and forms a central portion of the first intervening member 40. This one-side laminated portion pressing portion 41 is located on one side FH1 in the electrode body thickness direction FH of the electrode laminated portion 50e of the electrode body 50, and protrudes toward the other side FH2 in the electrode body thickness direction FH (toward the inner thickness direction CH3 of the case thickness direction CH) more than the base 43. Then, due to elastic compression by the first main wall portion 11 and the second main wall portion 12 of the case 10, the one-side laminated portion pressing portion 41 presses the central portion of the electrode laminated portion 50e of the electrode body 50 toward the other side FH2 in the electrode body thickness direction FH.

[0052] The one-side first R portion pressing portion 42A has an elongated rectangular shape and extends in the case width direction BH near an end of the upper side AH1 in the case height direction AH. This one-side first R portion pressing portion 42A is located on one side FH1 in the electrode body thickness direction FH further than the first electrode R portion 50rA of the electrode body 50, and protrudes toward the other side FH2 in the electrode body thickness direction FH further than the base 43 and further than the one-side laminate portion pressing portion 41. Due to elastic compression by the first main wall portion 11 and the second main wall portion 12 of the case 10, the one-side first R portion pressing portion 42A presses the first electrode R portion 50rA of the electrode body 50 toward the other side FH2 in the electrode body thickness direction FH.

[0053] The one-side second R portion pressing portion 42B has an elongated rectangular shape and extends in the case width direction BH near an end of the lower side AH2 in the case height direction AH. This one-side second R portion pressing portion 42B is located on one side FH1 in the electrode body thickness direction FH further than the second electrode R portion 50rB of the electrode body 50, and protrudes toward the other side FH2 in the electrode body thickness direction FH further than the base 43 and further than the one-side laminate portion pressing portion 41. Due to elastic compression by the first main wall portion 11 and the second main wall portion 12 of the case 10, the one-side second R portion pressing portion 42B presses the second electrode R portion 50rB of the electrode body 50 toward the other side FH2 in the electrode body thickness direction FH.

[0054] The second intervening member 45 consists of an other-side laminated portion pressing portion (laminated portion pressing portion) 46, an other-side first R portion pressing portion (R portion pressing portion) 47A, an other-side second R portion pressing portion (R portion pressing portion) 47B, and a plate-shaped base 48 that forms the parts other than these pressing portions. Of these, the other-side laminate portion pressing portion 46 has a rectangular shape in a plan view and forms a central portion of the second intervening member 45. This other-side laminate portion pressing portion 46 is located on the other side FH2 in the electrode body thickness direction FH of the electrode laminate portion 50e of the electrode body 50, and protrudes toward one side FH1 in the electrode body thickness direction FH (toward the inner thickness direction CH3 in the case thickness direction CH) more than the base 48. Then, due to elastic compression by the first main wall portion 11 and the second main wall portion 12 of the case 10, the other-side laminate portion pressing portion 46 presses the central portion of the electrode laminate portion 50e of the electrode body 50 toward one side FH1 in the electrode body thickness direction FH.

[0055] The other-side first R portion pressing portion 47A has an elongated rectangular shape and extends in the case width direction BH near an end of the upper side AH1 in the case height direction AH. This other-side first R portion pressing portion 47A is located on the other side FH2 in the electrode body thickness direction FH further than the first electrode R portion 50rA of the electrode body 50, and protrudes toward one side FH1 in the electrode body thickness direction FH further than the base 48 and further than the other-side laminate portion pressing portion 46. Due to elastic compression by the first main wall portion 11 and second main wall portion 12 of the case 10, the other-side first R portion pressing portion 47A presses the first electrode R portion 50rA of the electrode body 50 toward one side FH1 in the electrode body thickness direction FH. Therefore, in this embodiment 1, the other-side first R portion pressing portion 47A and the aforementioned one-side first R portion pressing portion 42A clamp the first electrode R portion 50rA in the thickness direction FH of the electrode body, thereby appropriately pressing the first electrode R portion 50rA.

[0056] The other-side second R portion pressing portion 47B has an elongated rectangular shape and extends in the case width direction BH near an end of the lower side AH2 in the case height direction AH. This other-side second R portion pressing portion 47B is located on the other side FH2 in the electrode body thickness direction FH further than the second electrode R portion 50rB of the electrode body 50, and protrudes toward one side FH1 in the electrode body thickness direction FH further than the base 48 and further than the other-side laminate portion pressing portion 46. Due to elastic compression by the first main wall portion 11 and the second main wall portion 12 of the case 10, the other-side second R portion pressing portion 47B presses the second electrode R portion 50rB of the electrode body 50 toward one side FH1 in the electrode body thickness direction FH. Therefore, in this embodiment 1, the second electrode R portion 50rB is clamped in the thickness direction FH of the electrode body by this other-side second R portion pressing portion 47B and the aforementioned one-side second R portion pressing portion 42B, thereby appropriately pressing the second electrode R portion 50rB.

[0057] 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 body 50 in the electrode body thickness direction FH. That is, the battery 1 is a self-compressing type in which the battery 1 itself elastically compresses the electrode body 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.

[0058] The battery 1 also has laminate portion pressing portions (one-side laminate portion pressing portion 41 and other-side laminate portion pressing portion 46) that press the electrode laminate portion 50e of the electrode assembly 50, R portion pressing portions (one-side first R portion pressing portion 42A and other-side first R portion pressing portion 47A) that press the first electrode R portion 50rA of the electrode assembly 50, and R portion pressing portions (one-side second R portion pressing portion 42B and other-side second R portion pressing portion 47B) that press the second electrode R portion 50rB of the electrode assembly 50. Therefore, in addition to the electrode laminate portion 50e of the electrode assembly 50, the electrode R portions (the first electrode R portion 50rA and the second electrode R portion 50rB) of the electrode assembly 50 can also be pressed, allowing the electrode assembly 50 to be pressed over a wider area. This improves the charge / discharge cycle characteristics of the battery 1.

[0059] Furthermore, in the first embodiment, a first intervening member 40 is disposed between the first main wall portion 11 of the case 10 and the electrode body 50, and this first intervening member 40 is provided with a one-side laminated portion pressing portion 41, a one-side first R portion pressing portion 42A, and a one-side second R portion pressing portion 42B. Therefore, it is not necessary to provide a one-side laminated portion pressing portion, a one-side first R portion pressing portion, and a one-side second R portion pressing portion on the first main wall portion 11 of the case 10. Furthermore, a second intervening member 45 is disposed between the second main wall portion 12 of the case 10 and the electrode body 50, and this second intervening member 45 is provided with an other-side laminated portion pressing portion 46, an other-side first R portion pressing portion 47A, and an other-side second R portion pressing portion 47B. This eliminates the need to provide an other-side laminated portion pressing portion, an other-side first R portion pressing portion, and an other-side second R portion pressing portion on the second main wall portion 12 of the case 10.

[0060] In addition, in this embodiment 1, the first electrode R portion 50rA of the electrode body 50 is sandwiched in the electrode body thickness direction FH between the one-side first R portion pressing portion 42A and the other-side first R portion pressing portion 47A, so that the first electrode R portion 50rA can be pressed more appropriately. Also, the second electrode R portion 50rB of the electrode body 50 is sandwiched in the electrode body thickness direction FH between the one-side second R portion pressing portion 42B and the other-side second R portion pressing portion 47B, so that the second electrode R portion 50rB can be pressed more appropriately.

[0061] Next, a method for manufacturing the battery 1 will be described (see FIGS. 7 to 10). A main 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).

[0062] Then, in the "accommodating step S1" (see FIG. 7), the electrode assembly 50 wrapped in an insulating holder, the first intervening member 40, and the second intervening member 45 are accommodated in the main body member 21 to which the positive terminal 60 and the negative terminal 70 are fixed, with the first intervening member 40 and the second intervening member 45 overlapping the electrode assembly 50 (see FIG. 8). 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 second intervening member 45 is first accommodated in the main body member 21, and the electrode assembly 50 is then 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 assembly 50 is then overlapped on the second intervening member 45. Next, the first intervening member 40 is placed on top of the electrode body 50. Thereafter, 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.

[0063] Next, in the "pressure compression step S2" (see FIG. 7), the lid member 31 is placed on the second intervening member 45, the electrode assembly 50, and the first 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 second intervening member 45, the electrode assembly 50, and the first intervening member 40 in the electrode assembly thickness direction FH, thereby compressing the electrode assembly 50 (see FIG. 9). 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 base 510, and the external force Fa is applied to the first main wall portion 11 and the second main wall portion 12. Then, the second intervening member 45, the electrode body 50 and the first intervening member 40 are pressed in the electrode body thickness direction FH, compressing the electrode body 50 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 10).

[0064] Next, in the "joining step S3" (see FIG. 7), 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. 10). 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.

[0065] Next, in the "release step S4" (see FIG. 7), 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 body 50 does not return to its original state (thickness). After the external force Fa is released, the electrode body 50 is elastically compressed by the first main wall portion 11 and the second main wall portion 12 of the case 10.

[0066] 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.

[0067] In a conventional prismatic battery, the case 10 is configured by a bottomed, rectangular cylindrical 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, the first intervening member 40, and the second intervening member 45 in order to press and compress the electrode body 50 in the assembled battery, making it difficult to insert the electrode body 50, the first intervening member 40, and the second intervening member 45 into the body member.

[0068] In contrast, in the manufacturing method of the battery 1 described above, in the housing step S1, the electrode body 50, the first intervening member 40, and the second intervening member 45 are housed in the main body member 21, which is a bottomed, square tube-shaped body member 21 that forms the second main wall portion 12 and the four side wall portions 13 to 16, so that the electrode body 50, the first intervening member 40, and the second intervening member 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 in which the electrode body 50 is elastically compressed by the battery 1 itself can be easily manufactured.

[0069] Furthermore, in this embodiment 1, the battery 1 is manufactured using the first intervening member 40, so that the battery 1 can be manufactured in which the electrode laminated portion 50e, the first electrode R portion 50rA, and the second electrode R portion 50rB of the electrode body 50 are appropriately pressed by the one-side laminated portion pressing portion 41, the one-side first R portion pressing portion 42A, and the one-side second R portion pressing portion 42B of the first intervening member 40. Furthermore, since the battery 1 is manufactured using the second intervening member 45, the battery 1 can be manufactured in which the electrode laminated portion 50e, the first electrode R portion 50rA, and the second electrode R portion 50rB of the electrode body 50 are appropriately pressed by the other-side laminated portion pressing portion 46, the other-side first R portion pressing portion 47A, and the other-side second R portion pressing portion 47B of the second intervening member 45.

[0070] Furthermore, in the first embodiment, the first electrode R portion 50rA of the electrode body 50 is sandwiched in the electrode body thickness direction FH between the one-side first R portion pressing portion 42A and the other-side first R portion pressing portion 47A, and the second electrode R portion 50rB of the electrode body 50 is sandwiched in the electrode body thickness direction FH between the one-side second R portion pressing portion 42B and the other-side second R portion pressing portion 47B. This makes it possible to manufacture a battery 1 in which the first electrode R portion 50rA and the second electrode R portion 50rB are more appropriately pressed.

[0071] (Embodiment 2) Next, a second embodiment will be described (see FIGS. 11 to 13). Descriptions of parts similar to those of the first embodiment will be omitted or simplified. In the battery 1 of the first embodiment, a first intervening member 40 is disposed between the first main wall portion 11 of the case 10 and the electrode assembly 50, and a second intervening member 45 is disposed between the second main wall portion 12 of the case 10 and the electrode assembly 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 body 50. Meanwhile, in the second embodiment, the configuration of the case 110 differs from that of the case 10 of the first embodiment, and the first main wall portion 111 of the case 110 is provided with a one-side stacked portion pressing portion (stacked portion pressing portion) 141, a one-side first R portion pressing portion (R portion pressing portion) 142A, and a one-side second R portion pressing portion (R portion pressing portion) 142B, and the second main wall portion 112 of the case 110 is provided with an other-side stacked portion pressing portion (stacked portion pressing portion) 146, an other-side first R portion pressing portion (R portion pressing portion) 147A, and an other-side second R portion pressing portion (R portion pressing portion) 147B.

[0072] Specifically, the first main wall portion 111 of the case 110 of the second embodiment has a rectangular one-side laminated portion pressing portion 141 in the central portion of the first main wall portion 111. This one-side laminated portion pressing portion 141 is located on one side FH1 in the electrode body thickness direction FH relative to the electrode laminated portion 50e of the electrode body 50, and protrudes toward the other side FH2 in the electrode body thickness direction FH. Then, due to elastic compression by the first main wall portion 111 and the second main wall portion 112 of the case 110, the one-side laminated portion pressing portion 141 presses the central portion of the electrode laminated portion 50e of the electrode body 50 toward the other side FH2 in the electrode body thickness direction FH.

[0073] Furthermore, the first main wall portion 111 of the case 110 has a long, narrow, rectangular one-side R portion pressing portion 142A extending in the case width direction BH near an end of the upper side AH1 in the case height direction AH. This one-side first R portion pressing portion 142A is located on one side FH1 in the electrode body thickness direction FH relative to the first electrode R portion 50rA of the electrode body 50 and protrudes toward the other side FH2 in the electrode body thickness direction FH. Due to elastic compression by the first main wall portion 111 and the second main wall portion 112 of the case 110, the one-side first R portion pressing portion 142A presses the first electrode R portion 50rA of the electrode body 50 toward the other side FH2 in the electrode body thickness direction FH.

[0074] The first main wall portion 111 of the case 110 also has a narrow rectangular other-side first R-portion pressing portion 142B extending in the case width direction BH near an end portion on the lower side AH2 in the case height direction AH. This other-side second R-portion pressing portion 142B is located on one side FH1 in the electrode body thickness direction FH relative to the second electrode R portion 50rB of the electrode body 50, and protrudes toward the other side FH2 in the electrode body thickness direction FH. Due to elastic compression by the first main wall portion 111 and the second main wall portion 112 of the case 110, the one-side second R-portion pressing portion 142B presses the second electrode R portion 50rB of the electrode body 50 toward the other side FH2 in the electrode body thickness direction FH.

[0075] The second main wall portion 112 of the case 110 has a rectangular other-side laminated portion pressing portion 146 in the center portion of the second main wall portion 112. This other-side laminated portion pressing portion 146 is located on the other side FH2 in the electrode body thickness direction FH relative to the electrode laminated portion 50e of the electrode body 50, and protrudes toward one side FH1 in the electrode body thickness direction FH. Due to elastic compression by the first main wall portion 111 and the second main wall portion 112 of the case 110, the other-side laminated portion pressing portion 146 presses the center portion of the electrode laminated portion 50e of the electrode body 50 toward one side FH1 in the electrode body thickness direction FH.

[0076] Furthermore, the second main wall portion 112 of the case 110 has an elongated rectangular other-side first R-portion pressing portion 147A extending in the case width direction BH near an end portion of the upper side AH1 in the case height direction AH. This other-side first R-portion pressing portion 147A is located on the other side FH2 in the electrode body thickness direction FH relative to the first electrode R portion 50rA of the electrode body 50, and protrudes toward one side FH1 in the electrode body thickness direction FH. Due to elastic compression by the first main wall portion 111 and the second main wall portion 112 of the case 110, the other-side first R-portion pressing portion 147A presses the first electrode R portion 50rA of the electrode body 50 toward one side FH1 in the electrode body thickness direction FH.

[0077] The first main wall portion 111 of the case 110 also has an elongated rectangular other-side first R-portion pressing portion 147B extending in the case width direction BH near an end portion on the lower side AH2 in the case height direction AH. This other-side second R-portion pressing portion 146B is located on the other side FH2 in the electrode body thickness direction FH relative to the second electrode R portion 50rB of the electrode body 50, and protrudes toward one side FH1 in the electrode body thickness direction FH. Due to elastic compression by the first main wall portion 111 and the second main wall portion 112 of the case 110, the other-side second R-portion pressing portion 147B presses the second electrode R portion 50rB of the electrode body 50 toward one side FH1 in the electrode body thickness direction FH.

[0078] 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 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 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 wall portions 13 to 16, the self-compressing battery 100 can be easily manufactured and can be made inexpensively.

[0079] The battery 100 also has laminate portion pressing portions (one-side laminate portion pressing portion 141 and the other-side laminate portion pressing portion 146) that press the electrode laminate portion 50e of the electrode body 50, R portion pressing portions (one-side first R portion pressing portion 142A and the other-side first R portion pressing portion 147A) that press the first electrode R portion 50rA of the electrode body 50, and R portion pressing portions (one-side second R portion pressing portion 142B and the other-side second R portion pressing portion 147B) that press the second electrode R portion 50rB of the electrode body 50. This allows the electrode body 50 to be pressed over a wider range, thereby improving the charge-discharge cycle characteristics of the battery 100.

[0080] Furthermore, in the second embodiment, a one-side laminated portion pressing portion 141, a one-side first R portion pressing portion 142A, and a one-side second R portion pressing portion 142B are provided on the first main wall portion 111 of the case 110. Therefore, there is no need to dispose an intervening member having a one-side laminated portion pressing portion, a one-side first R portion pressing portion, and a one-side second R portion pressing portion between the first main wall portion 111 and the electrode body 50. Furthermore, the second main wall 112 of the case 110 is provided with an other-side laminated portion pressing portion 146, an other-side first R portion pressing portion 147A, and an other-side second R portion pressing portion 147B. Therefore, there is no need to place an intervening member having an other-side laminated portion pressing portion, an other-side first R portion pressing portion, and an other-side second R portion pressing portion between the second main wall 112 and the electrode body 50.

[0081] Furthermore, in this embodiment 2, the first electrode R portion 50rA of the electrode body 50 is clamped in the electrode body thickness direction FH between the one-side first R portion pressing portion 142A and the other-side first R portion pressing portion 147A, and the second electrode R portion 50rB of the electrode body 50 is clamped in the electrode body thickness direction FH between the one-side second R portion pressing portion 142B and the other-side second R portion pressing portion 147B, so that the first electrode R portion 50rA and the second electrode R portion 50rB can be pressed more appropriately.

[0082] 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.

[0083] 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 assembly 50 in the electrode assembly thickness direction FH. In this process, in the second embodiment, the one-side laminated portion pressing portion 141 and the other-side laminated portion pressing portion 146 provided on the case 110 press the electrode laminated portion 50e of the electrode assembly 50 in the electrode assembly thickness direction FH. Furthermore, the one-side first R portion pressing portion 142A and the other-side first R portion pressing portion 147A provided on the case 110 press the first electrode R portion 50rA of the electrode assembly 50 in the electrode assembly thickness direction FH. Furthermore, the second electrode R portion 50rB of the electrode body 50 is pressed in the electrode body thickness direction FH by the one-side second R portion pressing portion 142B and the other-side second R portion pressing portion 147B provided on the case 110. Then, the entire periphery of 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 body member 121. This step is performed using a pressing device 500 (see FIG. 9) similar to that of the first embodiment.

[0084] 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.

[0085] In the manufacturing method of the battery 100 of the second embodiment, in the housing step S1, the electrode body 50 is housed in the body member 121, which is a bottomed square tube that forms the second main wall portion 112 and the 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 thereafter, the self-compressing battery 100 can be easily manufactured. In particular, in this embodiment 2, the intervening member forming the R-portion pressing portion and the intervening member forming the stacked portion pressing portion are not disposed inside the main body member 121, so that the accommodation step S1 and the pressing and compressing step S2 can be easily performed.

[0086] Furthermore, the first electrode R portion 50rA of the electrode body 50 is clamped in the electrode body thickness direction FH between the one-side first R portion pressing portion 142A and the other-side first R portion pressing portion 147A, and the second electrode R portion 50rB of the electrode body 50 is clamped in the electrode body thickness direction FH between the one-side second R portion pressing portion 142B and the other-side second R portion pressing portion 147B, so that a battery 100 can be manufactured in which the first electrode R portion 50rA and the second electrode R portion 50rB are more appropriately pressed. Other parts that are the same as those in the first embodiment have the same effects as those in the first embodiment.

[0087] 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. [Explanation of symbols]

[0088] 1,100 batteries (energy storage devices) 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 First intervening member 41,141 One side stacking part pressing part (stacking part pressing part) 42A, 142A One side first R part pressing part (One side R part pressing part, R part pressing part) 42B, 142B One side second R portion pressing portion (One side R portion pressing portion, R portion pressing portion) 45 Second intervening member 46,146 Other side stacked part pressing part (stacked part pressing part) 47A, 147A Other side first R portion pressing portion (other side R portion pressing portion, R portion pressing portion) 47B, 147B Second R-section pressing portion on the other side (Other side R-section pressing portion, R-section pressing portion) 50 Electrode body 50rA 1st electrode R section 50rB 2nd electrode R section 50e Electrode stacking section 51 Positive electrode plate (electrode plate) 54 Negative electrode plate (electrode plate) 57 Separator CH Case thickness direction FH Electrode body thickness direction FH1 (electrode body thickness direction) one side FH2 (electrode body thickness direction) other side Fa External Force S1 Storage process S2 Press compression process S3 joining process S4 release process

Claims

1. Case and an electrode body housed in the case, 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 pair of electrode R portions in which the positive electrode plate, the negative electrode plate, and the separator are bent into a semi-cylindrical shape and overlapped; and a rectangular parallelepiped electrode stacking portion located between the pair of electrode R portions, 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 body in a thickness direction of the electrode body, a laminated portion pressing portion that presses the electrode laminated portion of the electrode body in a thickness direction of the electrode body by elastic compression by the first main wall portion and the second main wall portion; an R portion pressing portion that presses the electrode R portion of the electrode body in the thickness direction of the electrode body by elastic compression by the first main wall portion and the second main wall portion; 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 body and / or between the second main wall portion of the case and the electrode body; The R-portion pressing portion is provided on the intervening member. Energy storage device.

3. The electricity storage device according to claim 1 , The R-portion pressing portion is provided on at least one of the first main wall portion and the second main wall portion of the case. Energy storage device.

4. The electricity storage device according to any one of claims 1 to 3, an intervening member is provided between the first main wall portion of the case and the electrode body and / or between the second main wall portion of the case and the electrode body; The stacked portion pressing portion is provided on the intervening member. Energy storage device.

5. The electricity storage device according to any one of claims 1 to 3, The stack pressing portion is provided on at least one of the first main wall portion and the second main wall portion of the case. Energy storage device.

6. The electricity storage device according to any one of claims 1 to 3, the R portion pressing portion, which is located on one side of the electrode R portion in the thickness direction of the electrode body, and presses the electrode R portion toward the other side in the thickness direction of the electrode body; and the R portion pressing portion is located on the other side of the electrode R portion in the thickness direction of the electrode body, and has an other-side R portion pressing portion that presses the electrode R portion toward one side in the thickness direction of the electrode body, The electrode R portion is sandwiched and pressed in the thickness direction of the electrode body by the one-side R portion pressing portion and the other-side R portion pressing portion. Energy storage device.

7. Case and an electrode body housed in the case, 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 pair of electrode R portions in which the positive electrode plate, the negative electrode plate, and the separator are bent into a semi-cylindrical shape and overlapped; and a rectangular parallelepiped electrode stacking portion located between the pair of electrode R portions, 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, 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 body in a thickness direction of the electrode body, a laminated portion pressing portion that presses the electrode laminated portion of the electrode body in a thickness direction of the electrode body by elastic compression by the first main wall portion and the second main wall portion; an R portion pressing portion that presses the electrode R portion of the electrode body in the thickness direction of the electrode body by elastic compression by the first main wall portion and the second main wall portion; 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 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.

8. A method for manufacturing the electricity storage device according to claim 7, The electricity storage device is an intervening member forming the R-portion pressing portion is provided between the first main wall portion of the case and the electrode body and / or between the second main wall portion of the case and the electrode body; The containing step includes: The electrode body and the interposing member are accommodated in a state where the interposing member is stacked on the electrode body; The pressing and compressing step The electrode body and the interposed member are pressed in the thickness direction of the electrode body. A method for manufacturing an electricity storage device.

9. A method for manufacturing the electricity storage device according to claim 7, the R-portion pressing portion is 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 R-portion pressing portion provided on the case presses the electrode R-portion of the electrode body in the thickness direction of the electrode body. A method for manufacturing an electricity storage device.

10. A method for manufacturing the electricity storage device according to any one of claims 7 to 9, The electricity storage device is an intervening member forming the laminated portion pressing portion is provided between the first main wall portion of the case and the electrode body and / or between the second main wall portion of the case and the electrode body; The containing step includes: The electrode body and the interposing member are accommodated in a state where the interposing member is stacked on the electrode body; The pressing and compressing step includes: The electrode body and the interposed member are pressed in the thickness direction of the electrode body. A method for manufacturing an electricity storage device.

11. A method for manufacturing the electricity storage device according to any one of claims 7 to 9, the stacked portion pressing portion is 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 laminated portion pressing portion provided on the case presses the electrode laminated portion of the electrode body in the thickness direction of the electrode body. A method for manufacturing an electricity storage device.

12. A method for manufacturing the electricity storage device according to any one of claims 7 to 9, The electricity storage device is the R portion pressing portion, which is located on one side of the electrode R portion in the thickness direction of the electrode body, and presses the electrode R portion toward the other side in the thickness direction of the electrode body; and the R portion pressing portion is located on the other side of the electrode R portion in the thickness direction of the electrode body, and has an other-side R portion pressing portion that presses the electrode R portion toward one side in the thickness direction of the electrode body, the electrode R portion is sandwiched and pressed in the thickness direction of the electrode body by the one-side R portion pressing portion and the other-side R portion pressing portion, The pressing and compressing step The electrode R portion is sandwiched and pressed in the thickness direction of the electrode body by the one-side R portion pressing portion and the other-side R portion pressing portion. A method for manufacturing an electricity storage device.

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