Energy storage module

Abstract

To provide a power storage module in which each power storage device elastically compresses an electrode laminate portion of an electrode body in the thickness direction of the electrode body by the power storage device itself.SOLUTION: A power storage module 100 includes a plurality of power storage devices 1. The power storage device 1 includes a case 10 in the shape of a rectangular parallelepiped box having a first main wall portion 11, a second main wall portion 12, and four side walls 13 to 16, and an electrode body 50 having a rectangular parallelepiped electrode laminate portion 50e, and the electrode body 50 is accommodated in the case 10 in a position in which the electrode body thickness direction FH is parallel to the case thickness direction CH, and the power storage device 1 is formed by elastically compressing the electrode laminate portion 50e of the electrode body 50 in the electrode body thickness direction FH between the first main wall portion 11 and the second main wall portion 12 of the case 10.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to an electricity storage module including a plurality of rectangular electricity storage devices, each having an electrode body housed in a rectangular box-shaped case. [Background technology]

[0002] Battery modules are known in which multiple prismatic batteries, each with an electrode assembly housed in a rectangular box-shaped case, are stacked in the thickness direction of the case. Among these, battery modules, particularly those installed in vehicles and used over long periods of time, require the individual batteries to be compressed in the stacking direction for reasons such as improving the cycle characteristics of each battery. Specifically, the electrode stacking portions of the electrode assembly housed in the case must be compressed in the thickness direction of the electrode assembly. Therefore, in conventional battery modules, the stacked batteries are externally restrained using external restraining members consisting of a pair of end plates and multiple restraining bands, and the electrode stacking portions of each electrode assembly are compressed in the thickness direction of the electrode assembly. Examples of related prior art include Patent Documents 1 and 2 (see, for example, Figure 1 and Claim 1 of Patent Document 1 and Figure 1 and Claim 1 of Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-32581 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-91665 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a plurality of batteries constituting a battery module are externally restrained using restraining members, there are problems such as increased costs, increased size, increased weight, and an increased number of parts.

[0005] The present invention has been made in consideration of the current situation, and provides an energy storage module having a plurality of energy storage devices, in which each energy storage device elastically compresses the electrode stack portion of the electrode body in the thickness direction of the electrode body by the energy storage device itself. [Means for solving the problem]

[0006] (1) One aspect of the present invention for solving the above problem is an electricity storage module including a plurality of electricity storage devices, the electricity storage device including a rectangular parallelepiped box-shaped case and an electrode assembly housed in the case, the 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 a case thickness direction, the electrode assembly including electrode plates having a rectangular parallelepiped electrode stack portion in which the electrode plates are stacked in the electrode assembly thickness direction, and the electrode assembly is housed in the case with the electrode assembly thickness direction parallel to the case thickness direction, and the electricity storage device is configured such that the electrode stack portion of the electrode assembly is elastically compressed in the electrode assembly thickness direction by the first main wall portion and the second main wall portion of the case. The plurality of power storage devices are stacked in the case thickness direction, and at least one of the first main wall portion and the second main wall portion of the case of each power storage device has a case recess that is recessed toward the inside in the case thickness direction and forms a device cooling path for circulating cooling air between adjacent power storage devices. It is a storage module.

[0007] In the electricity storage devices constituting the above-described electricity storage module, the first and second main walls of the case elastically compress the electrode stack portion of the electrode body in the thickness direction of the electrode body. That is, the electricity storage device is a self-compressing type in which the electricity storage device itself elastically compresses the electrode stack portion of the electrode body. Therefore, the electricity storage module does not need to compress the electrode stack portion of the electrode body of each electricity storage device using a restraining member, and therefore does not require the use of a restraining member, or external restraint by a simple restraining member is sufficient. Furthermore, in conventional battery modules, spacers are placed between adjacent power storage devices, and these spacers form device cooling paths between adjacent batteries through which cooling air circulates (see Figure 1 and claim 1 of Patent Document 1, and Figure 1 and claim 1 of Patent Document 2, etc.). In contrast, in the above-described energy storage module, the above-described case recess is provided in at least one of the first main wall portion and the second main wall portion of the case of the energy storage device, and this case recess forms a device cooling path for cooling air between adjacent energy storage devices, so there is no need to place a spacer forming a device cooling path between adjacent energy storage devices.

[0008] Examples of the "electricity storage device" include secondary batteries such as lithium ion secondary batteries, sodium ion secondary batteries, and calcium ion secondary batteries, and capacitors such as lithium ion capacitors.

[0009] (2) Furthermore, in the energy storage module described in (1), the case of the energy storage device may be an energy storage module having a case body member in the shape of a rectangular cylinder with a bottom, which 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 lid member which 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 case body member.

[0010] The energy storage device constituting the above-mentioned energy storage module has a case in which a cover member forming the first main wall is joined to a case body member forming the second main wall and four side wall portions, so that a self-compressing energy storage device can be easily manufactured, resulting in an inexpensive energy storage module.

[0013] (3) Furthermore, (1) or (2) In the energy storage module described in the above, the energy storage device is fixed to one of the side wall portions of the case, is connected to the electrode body within the case, and has an electrode terminal that extends through the side wall portion to the outside of the case, and the case recess has a configuration that cools the electrode terminal by the cooling air flowing out from the outlet of the device cooling path or by the cooling air flowing into the inlet of the device cooling path.

[0014] In the above-described electricity storage module, the case recess has the above-described shape, so that the electrode terminals can be cooled by cooling air.

[0015] (4) Furthermore (1) (3) In the electric storage module according to any one of the above items, an insulating layer may be provided on a surface of the case of the electric storage device to insulate the electric storage device from other adjacent electric storage devices.

[0016] In the above-described electricity storage module, the above-described insulating layer is provided on the surface of the case of the electricity storage device, so that the cases of adjacent electricity storage devices can be electrically insulated from each other.

[0017] Examples of the "insulating layer" include an insulating layer made of an insulating film formed by adhering an insulating film to the surface of the case, an insulating layer made of part of a shrink film provided on the surface of the case by wrapping the case in shrink film, and an insulating layer formed by coating the surface of the case with a resin. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a perspective view of the battery according to the embodiment, seen from the first main wall side. [Figure 2] FIG. 2 is a perspective view of the battery according to the embodiment, seen from the second main wall side. [Figure 3] FIG. 2 is a plan view of a first main wall portion of a case of the battery according to the embodiment. [Figure 4] FIG. 3 is a plan view of a second main wall portion of the case of the battery according to the embodiment. [Figure 5] FIG. 2 is a top view of the battery according to the embodiment. [Figure 6] FIG. 2 is a bottom view of the battery according to the embodiment. [Figure 7] 5 is a cross-sectional view taken along the arrows AA in FIGS. 1 to 4, taken along the case width direction and case thickness direction of the battery according to the embodiment. FIG. [Figure 8] FIG. 1 is an exploded perspective view of a battery according to an embodiment. [Figure 9] FIG. 2 is a perspective view of an electrode body according to an embodiment. [Figure 10] FIG. 2 is a top view of a plurality of batteries stacked in the case thickness direction. [Figure 11] FIG. 2 is a bottom view of a plurality of batteries stacked in the case thickness direction. [Figure 12] FIG. 2 is a partially cutaway cross-sectional view of a battery module according to the embodiment. [Figure 13] 10 is an explanatory diagram showing the state in which the electrode assembly is housed in the case body member, in relation to the manufacturing method of the battery according to the embodiment. FIG. [Figure 14] 10A and 10B are explanatory views showing how an external force is applied to press the electrode body in the thickness direction of the electrode body, in the method for manufacturing a battery according to the embodiment. [Figure 15] 10 is an explanatory diagram showing how the lid peripheral portion of the lid member is laser-welded to the opening peripheral portion of the case body member in the manufacturing method of the battery according to the embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show perspective views of a battery (energy storage device) 1 according to this embodiment. FIG. 3 shows a plan view of a first main wall portion 11 of a case 10 of the battery 1, FIG. 4 shows a plan view of a second main wall portion 12 of the case 10 of the battery 1, FIG. 5 shows a top view of the battery 1, and FIG. 6 shows a bottom view of the battery 1. FIG. 7 shows a cross-sectional view of the battery 1, and FIG. 8 shows an exploded perspective view of the battery 1. FIG. 9 shows a perspective view of an electrode assembly 50. FIGS. 10 and 11 show top and bottom views of multiple batteries 1 stacked in the case thickness direction CH. FIG. 12 shows a partially cutaway cross-sectional view of a battery module (energy storage module) 100 according to this embodiment. 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 are defined as directions shown in FIGS. 1 to 12.

[0020] The battery 1 is a rectangular (rectangular) sealed lithium ion secondary battery. The battery module 100 includes a plurality of batteries 1. This battery module 100 is mounted on vehicles such as hybrid cars, plug-in hybrid cars, and electric cars. First, we will explain the battery 1. This battery 1 is composed of a case 10, a flat wound electrode assembly 50 housed in the case 10, and a positive electrode terminal (electrode terminal) 60 and a negative electrode terminal (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 inside the case 10. An electrolyte 3 is also housed inside the case 10, a portion of which is impregnated into the electrode assembly 50 and the remainder of which is collected on a second side wall portion 14, which is the bottom wall portion of the case 10.

[0021] Of these, the case 10 is made of metal (aluminum in this embodiment). 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 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 8, the rear right side in FIG. 2, the lower side in FIG. 5, and the upper side in FIGS. 6 and 7), 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 8, the front left side in FIG. 2, the upper side in FIG. 5, and the lower side in FIGS. 6 and 7).

[0022] 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.

[0023] This case 10 is composed of a rectangular opening 21c, a squared-cylindrical case body member 21, and a rectangular lid member 31. Of these, the case body member 21 forms the second main wall portion 12 and four side wall portions 13-16, and the opening 21c of the case body member 21 is composed of the four side wall portions 13-16. On the other hand, the lid member 31 forms the first main wall portion 11 and closes the opening 21c of the case 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 case body member 21.

[0024] 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. 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 within the case 10, and also extends outside the case 10 by penetrating the first side wall 13.

[0025] 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 within the case 10, and also extends outside the case 10 by penetrating the first side wall 13.

[0026] The first main wall portion 11 of the case 10 is provided with a case recess 11e recessed toward the inner side CH3 in the case thickness direction CH (see FIGS. 1, 3, 7, and 8). This case recess 11e forms the center of the first main wall portion 11 excluding the peripheral portion 11s of the first main wall portion 11. The case recess 11e faces the electrode stack portion 50e of the electrode assembly 50, and elastic compression by the first main wall portion 11 and the second main wall portion 12 of the case 10 presses the electrode stack portion 50e in the electrode assembly thickness direction FH.

[0027] The second main wall portion 12 of the case 10 is provided with a case recess 12e recessed toward the inner side CH3 in the case thickness direction CH (see FIGS. 2, 4 to 8, 10, and 11). The case recess 12e includes a first recess 12e1 forming a central portion of the second main wall portion 12, a second recess 12e2 located on a lower side AH2 in the case height direction AH and at the center in the case width direction BH within the peripheral portion of the second main wall portion 12, and a third recess 12e3 located on an upper side AH1 in the case height direction AH and near both ends in the case width direction BH (near the positive electrode terminal 60 and the negative electrode terminal 70) within the peripheral portion of the second main wall portion 12. Note that the portions of the peripheral portion of the second main wall portion 12 that are not recessed toward the inner side CH3 in the thickness direction CH, excluding the second recess 12e2 and the third recess 12e3, are partial peripheral portions 12s. The first recess 12e1 of the case recess 12e faces the electrode stacking portion 50e of the electrode body 50, and elastic compression by the first main wall portion 11 and the second main wall portion 12 of the case 10 presses the electrode stacking portion 50e in the thickness direction FH of the electrode body.

[0028] When multiple batteries 1 are stacked in the same orientation in the case thickness direction CH (see FIGS. 10 to 12), the case recesses 11e, 12e form a device cooling path 130 that circulates cooling air AR between adjacent batteries 1. This device cooling path 130 has a cooling section 130a that circulates the cooling air AR to cool the electrode stack section 50e of the electrode assembly 50, one inlet 130b that allows the cooling air AR to flow into the cooling section 130a from outside the device cooling path 130 (specifically, from the lower side AH2 in the case height direction AH), and two outlets 130c that allow the cooling air AR in the cooling section 130a to flow out of the device cooling path 130 (specifically, to the upper side AH1 in the case height direction AH).

[0029] The cooling section 130a of the device cooling path 130 is a rectangular parallelepiped space formed by the case recess 11e of the first main wall portion 11 of one battery 1 facing the first recess 12e1 of the case recess 12e of the second main wall portion 12 of another adjacent battery 1. The inlet 130b of the device cooling path 130 is formed by the peripheral portion 11s of the first main wall portion 11 of one battery 1 facing the second recess 12e2 of the case recess 12e of the second main wall portion 12 of the other adjacent battery 1. The two outlets 130c of the device cooling path 130 are formed by the peripheral portion 11s of the first main wall portion 11 of one battery 1 facing the third recess 12e3 of the case recess 12e of the second main wall portion 12 of the other adjacent battery 1.

[0030] An insulating layer 80 is formed on the surface 10m of the case 10, specifically, on the surface 12sm of the partial peripheral portion 12s of the second main wall portion 12. This insulating layer 80 is made of an insulating film attached to the surface 12sm of the partial peripheral portion 12s. Therefore, when multiple batteries 1 are stacked in the case thickness direction CH, the cases 10 of adjacent batteries 1, specifically, the peripheral portion 11s of the first main wall portion 11 of one battery 1 and the partial peripheral portion 12s of the second main wall portion 12 of the other battery 1, do not directly abut on each other but abut via the insulating layer 80. This allows the cases 10 of adjacent batteries 1 to be electrically insulated from each other.

[0031] Next, the electrode assembly 50 will be described (see FIGS. 1 and 7 to 9). The 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 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 semicylindrical portion in which the positive electrode plate 51, the negative electrode plate 54, and the separator 57 are stacked while being bent into a semicylindrical shape. Meanwhile, the electrode stacking portion 50e is a rectangular parallelepiped portion in which 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.

[0032] The electrode assembly 50 is housed in the case 10 in an orientation in which 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. 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 stack portion 50e of the electrode assembly 50 in the electrode assembly thickness direction FH.

[0033] 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.

[0034] 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.

[0035] Next, the battery module 100 will be described (see Fig. 12, Fig. 10 and Fig. 11). The battery module 100 includes a plurality of batteries 1 stacked in the case thickness direction CH, and a pack case 110 that houses the batteries 1. The pack case 110 is made of resin and has a squared cylindrical shape with a rectangular opening 110c. The bottom wall 111 of the pack case 110 is provided with a plurality of through holes 111h. The positive electrode terminals 60 and the negative electrode terminals 70 of the batteries 1 stacked in the case thickness direction CH are electrically connected to each other via bus bars (conductive connecting members) 120, and the batteries 1 constituting the battery module 100 are connected in parallel. The bus bars 120 are rectangular plate-shaped, and the bus bars 120 and the positive electrode terminals 60 or the negative electrode terminals 70 are joined by welding.

[0036] As described above, each battery 1 has a case recess 11e in the first main wall 11 and a case recess 12e in the second main wall 12. Therefore, a device cooling path 130 for circulating cooling air AR is formed between adjacent batteries 1 in the battery module 100. As described above, the device cooling path 130 has a cooling section 130a, one inlet 130b, and two outlets 130c. When cooling air AR is supplied to the bottom wall 111 of the pack case 110 from the lower side AH2 toward the upper side AH1, the cooling air AR flows into the pack case 110 through the through-holes 111h formed in the bottom wall 111 of the pack case 110. Furthermore, the cooling air AR flows into the cooling section 130a of each device cooling path 130 through the inlet 130b of each device cooling path 130 formed between adjacent batteries 1.

[0037] The cooling air AR then flows out of the device cooling path 130 (to the upper side AH1) through the two outlets 130c. A portion of the cooling air AR flowing out from each outlet 130c comes into contact with the positive electrode terminal 60 or the negative electrode terminal 70 located near the outlet 130c, and thus the positive electrode terminal 60 and the negative electrode terminal 70 can be cooled by this cooling air AR. The cooling air AR also comes into contact with the bus bar 120, and therefore the bus bar 120 can be cooled, and thereby the positive electrode terminal 60 and the negative electrode terminal 70 can be indirectly cooled.

[0038] As described above, in each battery 1 constituting the battery module 100, the electrode stack portion 50e of the electrode assembly 50 is elastically compressed in the electrode assembly thickness direction FH by the first main wall portion 11 and the second main wall portion 12 of the case 10. That is, each battery 1 is a self-compressing type in which the battery 1 itself elastically compresses the electrode stack portion 50e of the electrode assembly 50. Therefore, the battery module 100 does not need to compress the electrode stack portion 50e of the electrode assembly 50 of each battery 1 with a restraining member, and simple external restraint of simply housing the stacked batteries 1 in the pack case 110 is sufficient.

[0039] Furthermore, in this embodiment, each battery 1 has a case 10 in which a cover member 31 forming the first main wall portion 11 is joined to a case body member 21 having a second main wall portion 12 and four side wall portions 13 to 16. Therefore, as will be described later, a self-compressing battery 1 can be easily manufactured, resulting in an inexpensive battery module 100. Furthermore, in this embodiment, case recesses 11e, 12e are provided in the first main wall portion 11 and the second main wall portion 12 of the case 10 of each battery 1, and these case recesses 11e, 12e form device cooling paths 130 for cooling air AR between adjacent batteries 1. Therefore, it is not necessary to place a spacer forming a device cooling path between adjacent batteries 1.

[0040] In this embodiment, the case recesses 11e, 12e provided in each battery 1 have a configuration that cools the positive electrode terminal 60 and the negative electrode terminal 70 with the cooling air AR flowing out from the outlet 130c of the device cooling path 130. Therefore, the battery module 100 can cool the positive electrode terminal 60 and the negative electrode terminal 70 with the cooling air AR flowing out from the outlet 130c. Furthermore, in this embodiment, an insulating layer 80 is provided on the surface 10m of the case 10 of each battery 1 (specifically, the surface 12sm of the partial peripheral portion 12s of the second main wall portion 12), and the cases 10 of adjacent batteries 1 abut against each other via the insulating layer 80, so that the cases 10 of adjacent batteries 1 can be electrically insulated from each other.

[0041] Next, a method for manufacturing the battery 1 and battery module 100 will be described (see FIGS. 13 to 15). First, the battery 1 is manufactured. That is, a case 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. Furthermore, this electrode assembly 50 is wrapped in a bag-shaped insulating holder (not shown).

[0042] The electrode assembly 50 wrapped in an insulating holder is then housed within the case body member 21 to which the positive terminal 60 and the negative terminal 70 are fixed (see FIG. 13). Specifically, the case body member 21 is placed on the flat mounting base 510 of the pressing device 500 with the entire second main wall portion 12 abutting against the mounting base 510. The electrode assembly 50 is then housed within the case body member 21 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 positive current collecting portion 50c of the electrode assembly 50 is then connected to the positive terminal 60 fixed to the case body member 21 by laser welding. The negative current collecting portion 50d of the electrode assembly 50 is also connected to the negative terminal 70 fixed to the case body member 21 by laser welding.

[0043] Next, the lid member 31 is placed on the electrode assembly 50 housed in the case 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 case body member 21 to press and compress the electrode stack portion 50e of the electrode assembly 50 in the electrode body thickness direction FH (see FIG. 14 ). 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 case body member 21 are sandwiched between the pressing portion 520 and the mounting base 510, and an external force Fa is applied to the first main wall portion 11 and the second main wall portion 12. Then, the electrode stacking portion 50e of the electrode body 50 is pressed and compressed in the electrode body thickness direction FH, and the entire periphery of the lid peripheral portion 31f of the lid member 31 is brought into contact with the opening peripheral portion 21f of the opening 21c of the case body member 21 (see FIG. 15).

[0044] Next, with the electrode body 50 pressed and compressed by the pressing device 500, the lid peripheral portion 31f of the lid member 31 is joined to the opening peripheral portion 21f of the case body member 21 over the entire circumference, thereby forming the case 10 (see FIG. 15). In this embodiment, 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. Thereafter, 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, since the case 10 has already been formed, the compressed electrode body 50 does not return to its original state (thickness). After the external force Fa is released, the electrode stack portion 50e of 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.

[0045] Next, 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 airtightly seal the gap between the sealing member 18 and the case 10. Also, an insulating film is attached to the surface 12sm of the partial peripheral portion 12s of the second main wall portion 12 of the case 10, to form an insulating layer 80. Next, a charging device (not shown) is connected to the battery 1 to initially charge the battery 1. After that, the initially charged battery 1 is left to stand for a predetermined time to age the battery 1.

[0046] Next, multiple batteries 1 are stacked in the same orientation in the case thickness direction CH and housed in a pack case 110 (see FIG. 12). After that, the positive electrode terminals 60 and negative electrode terminals 70 of each battery 1 are connected to each other using bus bars 120. Specifically, the bus bars 120 are welded to each positive electrode terminal 60 or each negative electrode terminal 70. In this way, the battery module 100 is completed.

[0047] Although the present invention has been described above in accordance with the embodiments, it goes without saying that the present invention is not limited to the embodiments and can be modified and applied as appropriate within the scope of the invention. For example, in the embodiment, the flat wound electrode body 50 is exemplified as the electrode body, but the present invention is not limited to this. The electrode body may be, for example, a laminated electrode body in which a plurality of rectangular positive electrode plates (electrode plates) and a plurality of rectangular negative electrode plates (electrode plates) are laminated with rectangular separators interposed therebetween.

[0048] Furthermore, in the embodiment, the battery module 100 in which a plurality of batteries 1 are stacked in a single row has been exemplified, but a battery module in which a plurality of batteries 1 are stacked in multiple rows may also be used. Furthermore, in the embodiment, the plurality of batteries 1 constituting the battery module are connected in parallel, but the electrical connection between the batteries 1 is not limited to this, and the batteries 1 may also be connected in series.

[0049] In the embodiment, the first main wall portion 11 and the second main wall portion 12 of the case 10 are provided with the case recesses 11e, 12e, respectively, and these case recesses 11e, 12e form the device cooling path 130 for the cooling air AR, but this is not limitative. A case recess may be provided in only one of the first main wall portion 11 and the second main wall portion 12, and the device cooling path may be formed by this case recess.

[0050] In the embodiment, the positive electrode terminal 60 and the negative electrode terminal 70 are cooled by the cooling air AR flowing out from the outlet 130c of the device cooling path 130, but this is not limiting. It is also possible to adopt a configuration in which the positive electrode terminal and the negative electrode terminal are cooled by the cooling air AR flowing into the inlet of the device cooling path. [Explanation of symbols]

[0051] 1. Battery (energy storage device) 10 cases 10m (case) surface 11 First main wall 11e Case recess 12 Second main wall 12sm (surface of part of surrounding area) 12e Case recess 13 First side wall portion (upper wall portion) 14 Second side wall portion (bottom wall portion) 15 Third side wall 16 Fourth side wall 21 Case body material 21c opening 21f Opening edge 31 Cover member 31f Lid edge 50 Electrode body 50e Electrode stacking section 51 Positive electrode plate (electrode plate) 54 Negative electrode plate (electrode plate) 60 Positive terminal (electrode terminal) 70 Negative terminal (electrode terminal) 80 insulating layer 100 Battery module (storage module) 110 pack case 120 Bus bar (conductive connecting member) 130 Device cooling path 130a Cooling section 130b Inlet 130c Outlet CH Case thickness direction CH3 Inner side in thickness direction FH Electrode body thickness direction AR Cooling Air

Claims

1. A power storage module including a plurality of power storage devices, The electricity storage device is The battery includes a rectangular box-shaped case and an electrode assembly housed in the case, The above case is 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 a case thickness direction; The electrode body is Including an electrode plate, The electrode plates have a rectangular parallelepiped electrode laminated portion laminated 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 electricity storage device is 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, the plurality of power storage devices are stacked in the thickness direction of the case, At least one of the first main wall portion and the second main wall portion of the case of the power storage device has a case recess that is recessed toward the inside in the thickness direction of the case and forms a device cooling path through which cooling air circulates between adjacent power storage devices. Energy storage module.

2. The energy storage module according to claim 1, The case of the power storage device is a case body member having a rectangular cylindrical shape with a bottom, the case 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 case body member over the entire periphery; Energy storage module.

3. A storage module according to claim 1 or claim 2, The electricity storage device is an electrode terminal fixed to one of the side walls of the case, connected to the electrode body within the case, and extending to the outside of the case through the side wall; The case recess is The electrode terminal is cooled by the cooling air flowing out from an outlet of the device cooling path or by the cooling air flowing into an inlet of the device cooling path. Energy storage module.

4. The energy storage module according to claim 1 or 2, The surface of the case of the power storage device has an insulating layer that insulates the power storage device from other adjacent power storage devices. Energy storage module.

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