JP7559009B2 - Energy Storage Module - Google Patents

Description

The present invention relates to an energy storage module in which multiple energy storage devices, such as batteries and capacitors, are stacked in the thickness direction of the case and further restrained in the stacking direction by restraining devices.

Conventionally, in a battery module containing multiple rectangular batteries, the batteries are stacked straight in the case thickness direction so that the long case sides of the batteries overlap, and the remaining case top, case bottom, and pair of short case sides are aligned (flush) with adjacent batteries. The external electrode terminals of adjacent batteries are then electrically connected with conductive connecting members such as bus bars, and the battery assembly is compressed and restrained toward the inside in the stacking direction of the batteries using a pair of end plates and restraining devices such as restraining bands that span between them.

However, when charging, the electrode body contained in the battery expands in the electrode plate stacking direction, and the battery also expands in the battery case thickness direction, which is parallel to the electrode plate stacking direction, so the entire assembly of batteries stacked in the case thickness direction also tends to stretch in the stacking direction of the batteries. This causes large tensile forces to be applied to the restraining device that restrains the battery assembly in the stacking direction, and to the conductive connection members that connect the external electrode terminals of adjacent batteries, pulling them outward in the stacking direction. For this reason, it was necessary to make the restraining device, conductive connection members, and external electrode terminals of the batteries sturdy so that problems would not arise even if such tensile forces were applied.

In response to this, a battery module can be considered in which the batteries are stacked in the stacking direction while being arranged in a zigzag pattern in the case width direction perpendicular to the stacking direction, and then restrained in the stacking direction with restraining devices. A battery module of this type is disclosed in FIG. 2 of Patent Document 1, etc. If the batteries are stacked while being arranged in a zigzag pattern, the overlapping area between adjacent batteries is reduced, and the force that stretches the battery assembly in the stacking direction during charging is reduced, thereby reducing the above-mentioned tensile force applied to the restraining devices and conductive connection members. This makes it possible to simplify the restraining devices, conductive connection members, and external electrode terminals of the batteries.

JP 2012-156131 A

However, when the batteries are stacked in a zigzag arrangement, as shown in FIG. 2 of Patent Document 1, the conductive connection members are arranged at an angle to the stacking direction to connect the external electrode terminals. This requires the conductive connection members to be longer than when the batteries are stacked in a straight line, and this creates a new problem of increased weight for the battery module.

The present invention was made in consideration of this current situation, and provides an energy storage module that can reduce the length of the conductive connecting members and reduce the weight of the energy storage module compared to conventional energy storage modules in which multiple energy storage devices are stacked in a zigzag arrangement.

One aspect of the present invention for solving the above problem includes an electrode body including an electrode stacking portion in which a plurality of electrode plates are stacked in an electrode plate stacking direction, a case in which the electrode body is housed inside with the electrode plate stacking direction parallel to a case thickness direction, and three or more power storage devices having a pair of external electrode terminal portions fixed to one side of the case in a case height direction perpendicular to the case thickness direction, wherein the one side of each of the power storage devices in the case height direction is all in the same direction, the three or more power storage devices are stacked in a stacking direction parallel to the case thickness direction and are arranged in a zigzag pattern in a case width direction perpendicular to the case thickness direction and the case height direction, and the power storage devices .... and a restraining device that compresses and restrains the three or more stacked electricity storage devices toward the inside in the stacking direction, wherein the three or more electricity storage devices are electrically connected by the multiple conductive connection members in the stacking order of the electricity storage devices, and the three or more electricity storage devices arranged in a zigzag pattern in the case width direction have the external electrode terminals arranged in the case width direction at positions where the external electrode terminals of adjacent electricity storage devices are aligned in the stacking direction, and the conductive connection members extend in the stacking direction to connect the external electrode terminals of adjacent electricity storage devices aligned in the stacking direction. Alternatively, a plurality of power storage devices including an electrode assembly including an electrode stacking portion in which a plurality of electrode plates are stacked in an electrode plate stacking direction, a case in which the electrode assembly is housed inside with the electrode plate stacking direction parallel to a case thickness direction, and a pair of external electrode terminal portions fixed to one side of the case in a case height direction perpendicular to the case thickness direction, wherein the one side of each of the power storage devices in the case height direction is in the same direction, the power storage devices are stacked in a stacking direction parallel to the case thickness direction and are arranged in a zigzag pattern in a case width direction perpendicular to the case thickness direction and the case height direction, and the power storage devices adjacent to each other in the stacking direction have different poles or This is an energy storage module comprising: a conductive connection member connecting the external electrode terminal portions of the same polarity; and a restraining device compressing and restraining the stacked energy storage devices toward the inside in the stacking direction, wherein the multiple energy storage devices arranged in a zigzag pattern in the case width direction have a pair of the external electrode terminal portions provided asymmetrically with respect to the case width direction, and each of the external electrode terminal portions is arranged at a position in the case width direction where the external electrode terminal portions of adjacent energy storage devices are aligned in the stacking direction, and the conductive connection member extends in the stacking direction to connect the external electrode terminal portions of adjacent energy storage devices aligned in the stacking direction.

In the above-mentioned energy storage module, similarly to Patent Document 1, a plurality of energy storage devices are arranged in a zigzag pattern in the case width direction and stacked in the case thickness direction (stacking direction). Therefore, the force that causes the assembly of energy storage devices to stretch in the stacking direction during charging is smaller than when the energy storage devices are stacked straight in the stacking direction, and the tensile force that pulls the restraining device and the conductive connecting member outward in the stacking direction is smaller. Thus, the restraining device, the conductive connecting member, and the external electrode terminal portion of the energy storage module can be simplified.
In addition, in the above-mentioned energy storage module, the external electrode terminals of adjacent energy storage devices are aligned in the stacking direction, and the conductive connection members extend in the stacking direction to connect the external electrode terminals of adjacent energy storage devices aligned in the stacking direction. This allows the length of the conductive connection members to be shorter than when the conductive connection members extend obliquely with respect to the stacking direction, thereby making it possible to reduce the weight of the energy storage module.

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.
Examples of the "electrode body" include a flat wound electrode body in which one strip-shaped positive electrode plate and one strip-shaped negative electrode plate are wound flatly through a strip-shaped separator, and a laminated electrode body in which multiple rectangular electrode plates (for example, multiple rectangular positive electrode plates and multiple rectangular negative electrode plates) are laminated in a rectangular parallelepiped shape through a separator. The flat wound electrode body has a flat portion and a pair of R portions located on both sides of the flat portion, and the part of the flat portion where multiple electrode plates are laminated through a separator corresponds to the above-mentioned "electrode laminated portion". On the other hand, in the laminated electrode body, the part where multiple electrode plates are laminated through a separator corresponds to the above-mentioned "electrode body laminated portion". In addition, the power storage device may have a single electrode body or multiple electrode bodies.
Examples of the "case" include a case made of a metal can, a case made of a resin, and a case made of a laminate film.

The plurality of power storage devices may be stacked directly on one another, or may be stacked indirectly via spacers or the like.
The electrical connection between the power storage devices by the conductive connecting members may be in series or in parallel.
Examples of the "restraint device" include a restraint device having a pair of end plates and a restraint band or bolt spanning between them, and a rectangular ring-shaped or bottomed square tubular device case that restrains and houses an assembly of electricity storage devices inside.

FIG. 1 is a perspective view of a battery according to a first embodiment. 1 is a cross-sectional view taken along the case height direction and the case width direction of a battery according to a first embodiment. FIG. FIG. 2 is a top view of the battery module according to the first embodiment. FIG. 2 is a side view of the battery module according to the first embodiment. FIG. 11 is a perspective view of a battery according to a second embodiment. FIG. 11 is a top view of a battery module according to a second embodiment. FIG. 11 is a side view of a battery module according to a second embodiment.

(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) 200 according to the first embodiment, and Fig. 2 shows a cross-sectional view of the battery 200. Fig. 3 shows a top view of a battery module (electricity storage module) 1 according to the first embodiment, and Fig. 4 shows a side view of the battery module 1. In the following description, the case height direction AH, case width direction BH, and case thickness direction CH of the battery 200 are defined as the directions shown in Figs. 1 and 2, and the module height direction EH, module short side direction FH, and module longitudinal direction (battery stacking direction) GH of the battery module 1 are defined as the directions shown in Figs. 3 and 4.

The battery module 1 is a rectangular parallelepiped battery module that is installed in vehicles such as hybrid cars, plug-in hybrid cars, and electric cars. Each battery 200 included in the battery module 1 is a rectangular (flat rectangular) sealed lithium ion secondary battery.

First, the battery 200 will be described (see Figures 1 and 2). The battery 200 is composed of a case 210, an electrode body 230 housed in the case 210, and a pair of electrode terminals (positive terminal 240 and negative terminal 250) supported by the case 210. An electrolyte 205 is housed in the case 210, a portion of which is impregnated in the electrode body 230 and the remainder is stored at the bottom of the case 210. The electrode body 230 is covered by an insulating holder 235 formed by folding an insulating film into a bag shape that opens to the upper side (one side) AH1 in the case height direction AH.

The case 210 is a rectangular box made of metal (aluminum in this embodiment 1). The case 210 has a rectangular case upper part 211 located on the upper side AH1 of the case height direction AH, a rectangular case bottom part 212 facing the upper part 211, and four rectangular case sides (a pair of case long sides 213, 214 and a pair of case short sides 215, 216) connecting the upper part 211 and the lower part 212. The case 210 is a bottomed square cylinder having an opening 221c on the upper side AH1 of the case height direction AH, and is composed of a case body member 221 that forms the case bottom part 212, the case long sides 213, 214, and the case short sides 215, 216, and a rectangular plate-like case cover member 222 that is welded in a form that closes the opening 221c of the case body member 221 and forms the case upper part 211.

A positive electrode terminal 240 made of aluminum is fixed to the case upper portion 211 in a state insulated from the case 210 via an insulating member 245. The positive electrode terminal 240 has a rectangular plate-shaped external positive electrode terminal portion (external electrode terminal portion) 241 provided on the case upper portion 211, and an internal positive electrode terminal portion 242 that is disposed mainly inside the case 210 and connects to the external positive electrode terminal portion 241 by penetrating the case upper portion 211. The external positive electrode terminal portion 241 is provided in the case upper portion 211 near the end portion 211a of one side BH1 in the case width direction BH. The internal positive electrode terminal portion 242 is joined to the positive electrode tab 230a of the electrode body 230 inside the case 210 and is electrically connected.

In addition, a negative electrode terminal 250 made of copper is fixed to the case upper portion 211 in a state insulated from the case 210 via an insulating member 255. This negative electrode terminal 250 has a rectangular plate-shaped external negative electrode terminal portion (external electrode terminal portion) 251 provided on the case upper portion 211, and an internal negative electrode terminal portion 252 that is mainly disposed inside the case 210 and connects to the external negative electrode terminal portion 251 through the case upper portion 211. The external negative electrode terminal portion 251 is provided asymmetrically with respect to the external positive electrode terminal portion 241 at a position away from the end portion 211b of the other side BH2 of the case width direction BH in the case upper portion 211. Specifically, the distance DN1 from the end of the other side BH2 of the case width direction BH of the case 210 to the center of the case width direction BH of the external negative electrode terminal 251 is the distance DP1 from the end of one side BH1 of the case width direction BH of the case 210 to the center of the case width direction BH of the external positive electrode terminal 241 plus the distance D1 (DN1 = DP1 + D1). In this embodiment 1, this distance D1 is 1/5 of the width dimension Wa of the case width direction BH of the case 210 (D1 = Wa / 5). In addition, the internal negative electrode terminal 252 is joined to the negative electrode tab 230b of the electrode body 230 inside the case 210 and is electrically connected.

A safety valve 225 is provided in the case upper portion 211 at a midpoint in the case width direction BH between the external positive electrode terminal portion 241 and the external negative electrode terminal portion 251. This safety valve 225 is thinner than other portions of the case lid member 222, and is a non-returnable safety valve that breaks and opens when the internal pressure of the case 210 exceeds the valve opening pressure, releasing gas generated within the case 210 to the outside of the case 210.

The electrode body 230 is a flat rectangular parallelepiped, and is a laminated electrode body in which a plurality of rectangular positive electrode plates (electrode plates) 231 and a plurality of rectangular negative electrode plates (electrode plates) 232 are alternately laminated in the electrode plate lamination direction DH via rectangular separators 233 made of a resin porous film. The electrode laminated portion 230c is a portion of the electrode body 230 where the plurality of positive electrode plates 231 and the plurality of negative electrode plates 232 are laminated via the separators 233. The electrode body 230 is housed in the case 210 with the electrode plate lamination direction DH parallel to the case thickness direction CH. Therefore, in the battery 200 of this embodiment 1, the electrode body 230 expands in the electrode plate lamination direction DH during charging, and the battery 200 expands in the case thickness direction CH accordingly.

The positive electrode plate 231 has a positive electrode active material layer (not shown) on each of the two main surfaces of a positive electrode collector foil (not shown) made of rectangular aluminum foil. The extension portion of the positive electrode plate 231 extending to the upper side AH1 in the case height direction AH has no positive electrode active material layer in the thickness direction, and is a positive electrode exposed portion 231r in which the positive electrode collector foil is exposed in the thickness direction, and each positive electrode exposed portion 231r overlaps with each other in the thickness direction to form the above-mentioned positive electrode tab 230a. This positive electrode tab 230a is joined to the internal positive electrode terminal portion 242 of the positive electrode terminal 240 as described above.

The negative electrode plate 232 has a negative electrode active material layer (not shown) on each of the two main surfaces of a negative electrode current collector foil (not shown) made of rectangular copper foil. The extension portion of the negative electrode plate 232 that extends to the upper side AH1 in the case height direction AH has no negative electrode active material layer in the thickness direction, and is a negative electrode exposed portion 232r in which the negative electrode current collector foil is exposed in the thickness direction, and each negative electrode exposed portion 232r overlaps with each other in the thickness direction to form the aforementioned negative electrode tab 230b. This negative electrode tab 230b is joined to the internal negative electrode terminal portion 252 of the negative electrode terminal 250 as described above.

Next, a battery module 1 in which a plurality of batteries 200 are stacked and restrained by a restraining device 30 will be described (see Figs. 3 and 4). This battery module 1 includes a battery assembly 10 in which a plurality of batteries 200 are stacked in a stacking direction (module longitudinal direction) GH parallel to the case thickness direction CH, and a restraining device 30 that compresses and restrains the battery assembly 10 toward the inside GH1 of the stacking direction GH. In addition, the external positive terminal portion 241 of the positive terminal 240 and the internal negative terminal portion 252 of the negative terminal 250 of the batteries 200 adjacent to each other in the stacking direction GH are electrically connected via a bus bar (conductive connection member) 20, and each battery 200 constituting the battery assembly 10 is connected in series. In addition, a cooling member 40 is disposed in the gap between every other battery 200 adjacent to each other in the stacking direction GH.

The batteries 200 constituting the battery assembly 10 are stacked in the case thickness direction CH with the case height direction AH coinciding with the module height direction EH of the battery module 1, the case width direction BH coinciding with the module short side direction FH of the battery module 1, and the case thickness direction CH coinciding with the stacking direction (module longitudinal direction) GH of the battery modules 1. The batteries 200 are stacked with their orientations alternating so that the case long sides 213 or case long sides 214 of adjacent batteries 200 face each other (overlap). The batteries 200 are stacked so that the case tops 211 of the batteries 200 are flush and the case bottoms 212 of the batteries 200 are flush.

Moreover, the batteries 200 are arranged in a zigzag pattern in the case width direction BH. In the first embodiment, the positional deviation L of adjacent batteries 200 in the case width direction BH is set to 1/5 (L=Wa/5) of the width dimension Wa of the case 210. As a result, adjacent batteries 200 are arranged such that only a portion of the electrode laminated portion 230c of the electrode body 230 overlaps with each other in the stacking direction GH due to the positional deviation in the case width direction BH. Specifically, when the width dimension of the electrode laminated portion 230c in the case width direction BH is Wb (where Wb>L), the positional deviation (positional deviation amount L) of adjacent batteries 200 causes the electrode laminated portions 230c of adjacent batteries 200 to overlap with each other in the stacking direction GH over a width Wc=Wb-L.
In addition, the positional deviation L = Wa/5 in the case width direction BH of each battery 200 is the same as the distance D1 of the external negative terminal portion 251 described above (L = Wa/5 = D1), so in the battery assembly 10, the external positive terminal portion 241 of the positive terminal 240 and the external negative terminal portion 251 of the negative terminal 250 of adjacent batteries 200 are aligned in the stacking direction GH.

The bus bar 20 is a rectangular plate extending in the stacking direction GH, and connects the external positive electrode terminals 241 and external negative electrode terminals 251 of adjacent batteries 200 arranged in the stacking direction GH. In this embodiment 1, the bus bar 20 is joined to the external positive electrode terminals 241 and external negative electrode terminals 251 by welding.

The restraining device 30 has a pair of rectangular end plates 31 made of metal (aluminum in this embodiment 1) and a plurality of restraining bands 32 that are stretched between the end plates 31 and connect the end plates 31 to each other. The pair of end plates 31 are arranged on the outer side GH2 of the stacking direction GH of the battery assembly 10, and clamp the battery assembly 10 on the inner side GH1 of the stacking direction GH. The restraining bands 32 are strip-shaped and made of metal (aluminum in this embodiment 1). The restraining bands 32 are stretched in the stacking direction GH, and both ends 32a of the restraining bands 32 are fixed to the end plates 31 by bolts 33. As a result, each battery 200 constituting the battery assembly 10 is compressed in the stacking direction GH (the same as the case thickness direction CH and the electrode plate stacking direction DH), and the electrode stacking portion 230c of the electrode body 230 of each battery 200 is compressed in the electrode plate stacking direction DH.

The cooling member 40 is a rectangular parallelepiped made of metal (aluminum in this embodiment 1). This cooling member 40 is provided with a flow passage 40k that penetrates the cooling member 40 in the module height direction EH. By circulating a cooling medium (not shown) through this flow passage 40k, each battery 200 in contact with the cooling member 40 can be cooled.

In the battery module 1 of this embodiment 1, multiple batteries 200 are arranged in a zigzag pattern in the case width direction BH and stacked in the case thickness direction CH (stacking direction GH). As a result, the force that causes the battery assembly 10 to stretch in the stacking direction GH during charging is smaller than when the batteries 200 are stacked straight in the stacking direction GH, and the tensile force acting on the restraint 30 and bus bar 20 to pull them outward GH2 in the stacking direction GH is smaller. This allows the restraint 30, bus bar 20, and external positive terminal portion 241 and external negative terminal portion 251 of the battery 200 to be simplified.

In addition, in the battery module 1, the external positive electrode terminals 241 and external negative electrode terminals 251 of adjacent batteries 200 are aligned in the stacking direction GH, and each bus bar 20 extends in the stacking direction GH to connect the external positive electrode terminals 241 and external negative electrode terminals 251 of adjacent batteries 200 aligned in the stacking direction GH. As a result, the length of each bus bar 20 can be made shorter than when the bus bars 20 extend obliquely relative to the stacking direction GH, making the battery module 1 lighter.

Next, a method for manufacturing the battery 200 and the battery module 1 will be described. First, the battery 200 is manufactured. That is, the positive electrode plate 231, the negative electrode plate 232, and the separator 233 are laminated to form the electrode body 230. Next, the positive electrode terminal 240 and the negative electrode terminal 250 are fixed to the case lid member 222, and the positive electrode terminal 240 and the negative electrode terminal 250 are welded and connected to the positive electrode tab 230a and the negative electrode tab 230b of the electrode body 230, respectively. Next, the electrode body 230 is wrapped in a bag-shaped insulating holder 235, and these are inserted into a separately prepared case body member 221, and the opening 221c of the case body member 221 is blocked with the case lid member 222. Then, the case body member 221 and the case lid member 222 are welded around the entire circumference of the case lid member 222 to form the case 210. Next, electrolyte 205 is injected into case 210 through an injection hole (not shown), and the injection hole is sealed with a sealing member (not shown). After that, initial charging and various inspections are performed on battery 200. In this manner, battery 200 is manufactured.

Next, multiple batteries 200 are stacked in the case thickness direction CH (stacking direction GH), and cooling members 40 are placed in the gaps between adjacent batteries 200 in the stacking direction GH every other battery 200 to form a battery assembly 10. At this time, the batteries 200 are stacked so that the upper sides AH1 of the case height direction AH of each battery 200 are all in the same direction, and the case tops 211 and case bottoms 212 of each battery 200 are flush. In addition, the orientation of each battery 200 is alternated so that the case long sides 213 or case long sides 214 of adjacent batteries 200 face each other. In addition, each battery 200 is arranged in a zigzag pattern in the case width direction BH. The amount of positional misalignment L between adjacent batteries 200 in the case width direction BH is set to one-fifth of the width dimension Wa of the case 210 (L = Wa/5), and the external positive electrode terminal portion 241 and the external negative electrode terminal portion 251 of adjacent batteries 200 are aligned in the stacking direction GH.

Next, the battery assembly 10 is restrained by a restraining device 30. That is, a pair of end plates 31 are placed on both outer sides of the battery assembly 10 in the stacking direction GH, and the battery assembly 10 and the end plates 31 are compressed in the stacking direction GH using a compression device (not shown). In this state, multiple restraining bands 32 are stretched between the pair of end plates 31, and both ends 32a of the restraining bands 32 are fixed to the end plates 31 with bolts 33. The compression by the compression device is then released. Next, the bus bars 20 are welded to the external positive electrode terminal portions 241 and external negative electrode terminal portions 251 of adjacent batteries 200, respectively. In this manner, the battery module 1 is completed.

(Embodiment 2)
Next, a second embodiment will be described (see Figs. 5 to 7). Descriptions of parts similar to those of the first embodiment will be omitted or simplified. In the battery module 1 of the first embodiment, the battery module 1 is formed by stacking one type of battery 200, and these batteries 200 are connected in series. In contrast, in the battery module (energy storage module) 100 of the second embodiment, the battery module 100 is formed by alternately stacking two types of batteries 200, 300 having different electrode terminal shapes, and these batteries 200, 300 are connected in parallel.

Of the batteries 200 and 300 included in the battery module 100 of this embodiment 2, the battery 200 is the same as the battery 200 of embodiment 1. On the other hand, the battery 300 (see FIG. 5) differs from the battery 200 in the positions at which the external positive terminal portion (external electrode terminal portion) 341 of the positive terminal (electrode terminal) 340 and the external negative terminal portion (external electrode terminal portion) 351 of the negative terminal (electrode terminal) 350 are formed.

Specifically, the external negative terminal portion 351 of the battery 300 is provided in the case upper portion 211 near an end portion 211b on the other side BH2 in the case width direction BH.
On the other hand, the external positive electrode terminal 341 of the battery 300 is provided asymmetrically with respect to the external negative electrode terminal 351 at a position away from the end 211a of one side BH1 of the case width direction BH of the case upper part 211. Specifically, the distance DP2 from the end of one side BH1 of the case width direction BH of the case 210 to the center of the case width direction BH of the external positive electrode terminal 341 is a distance DN2 from the end of the other side BH2 of the case width direction BH of the case 210 to the center of the case width direction BH of the external negative electrode terminal 351, plus the distance D2 (DP2 = DN2 + D2). Note that the distance DN2 is the same as the distance DP1 in the battery 200 (DN2 = DP1). Furthermore, since distance D2 is the same as distance D1 in battery 200 (D2=D1), distance DP2 (=DN2+D2) is the same as distance DN1 (=DP1+D1) in battery 200 (DP2=DN1).
The safety valve 325 is provided in the case upper portion 211 at a middle portion between the external positive electrode terminal portion 341 and the external negative electrode terminal portion 351 in the case width direction BH.

In the battery module 100 of the second embodiment (see Figs. 6 and 7), a plurality of batteries 200 and a plurality of batteries 300 are alternately stacked in the case thickness direction CH (stacking direction GH) to form a battery assembly 110. Specifically, each of the batteries 200, 300 constituting the battery assembly 110 is stacked in the case thickness direction CH in such a manner that the case height direction AH coincides with the module height direction EH of the battery module 100, the case width direction BH coincides with the module short side direction FH of the battery module 100, and the case thickness direction CH coincides with the stacking direction (module longitudinal direction) GH of the battery module 100. In addition, each of the batteries 200, 300 is stacked so that the case long side portion 213 and the case long side portion 214 of the adjacent batteries 200 and 300 face each other (overlap). In addition, the batteries 200, 300 are stacked so that the case tops 211 of the batteries 200, 300 are flush and the case bottoms 212 of the batteries 200, 300 are flush.

The batteries 200, 300 are also arranged in a zigzag pattern in the case width direction BH. In the second embodiment as well, the positional deviation L between adjacent batteries 200, 300 in the case width direction BH is set to one-fifth (L=Wa/5) of the width dimension Wa of the case 210. As a result, the adjacent batteries 200, 300 are arranged such that only parts of the electrode stacked portions 230c of the electrode body 230 overlap each other in the stacking direction GH, as in the first embodiment.
In addition, the positional misalignment amount L = Wa/5 in the case width direction BH of each battery 200, 300 is the same as the distance D1 of the external negative terminal portion 251 of battery 200 and the distance D2 of the external positive terminal portion 341 of battery 300 (L = Wa/5 = D1 = D2), so in the battery assembly 110, the external positive terminal portions 241, 341 and the external negative terminal portions 251, 351 of adjacent batteries 200, 300 are each aligned in the stacking direction GH.

The battery module 100 of this embodiment 2 also has two bus bars 120 that extend in a strip shape in the stacking direction GH. One bus bar 120 connects the external positive electrode terminal parts 241, 341 that are aligned in a row in the stacking direction GH, and the other bus bar 120 connects the external negative electrode terminal parts 251, 351 that are aligned in a row in the stacking direction GH.

In the battery module 100 of the second embodiment, the batteries 200, 300 are also stacked in the case thickness direction CH (stacking direction GH) while being arranged in a zigzag pattern in the case width direction BH. This reduces the tensile force acting on the restraining device 30 and the bus bar 120 during charging, pulling them outward in the stacking direction GH2, and thus allows the restraining device 30, the bus bar 120, the external positive electrode terminals 241, 341, and the external negative electrode terminals 251, 351 to be simplified.
In addition, the external positive electrode terminal portions 241, 341 and the external negative electrode terminal portions 251, 351 of adjacent batteries 200, 300 are aligned in the stacking direction GH, and the bus bar 120 extends in the stacking direction GH to connect the external positive electrode terminal portions 241, 341 and the external negative electrode terminal portions 251, 351 to each other. This allows the length of the bus bar 120 to be shortened, and the battery module 100 to be made lighter. Other parts similar to those in the first embodiment provide the same effects as those in the first embodiment.

Although the present invention has been described above with reference to the first and second embodiments, it goes without saying that the present invention is not limited to the first and second embodiments, and can be modified as appropriate without departing from the spirit of the present invention.

1,100 Battery module (energy storage module)
20, 120 Bus bar (conductive connection member)
30 Restraint 200, 300 Battery (electricity storage device)
210 Case 211 Case upper part (one side part of the case in the case height direction)
230 Electrode body 230c Electrode laminate portion 231 Positive electrode plate (electrode plate)
232 Negative electrode plate (electrode plate)
240, 340 Positive terminal (electrode terminal)
241, 341 External positive electrode terminal section (external electrode terminal section)
250,350 Negative terminal (electrode terminal)
251,351 External negative terminal part (external electrode terminal part)
AH Case height direction AH1 Top side (one side)
BH: Case width direction CH: Case thickness direction DH: Electrode plate stacking direction GH: Module longitudinal direction (battery stacking direction)
GH1 (stack direction) inside GH2 (stack direction) outside

Claims (2)

an electrode assembly including an electrode laminated portion in which a plurality of electrode plates are laminated in an electrode plate lamination direction;
a case in which the electrode body is housed with the electrode plate lamination direction parallel to the case thickness direction; and
Three or more electricity storage devices each having a pair of external electrode terminals fixed to a portion of one side of the case in a case height direction perpendicular to the case thickness direction,
the one side of each of the power storage devices in the case height direction is in the same direction,
The stacking direction is parallel to the thickness direction of the case, and
three or more power storage devices arranged in a zigzag pattern in a case width direction perpendicular to the case thickness direction and the case height direction;
a plurality of conductive connection members that connect the external electrode terminal portions of the power storage devices of different poles or the same pole that are adjacent to each other in the stacking direction;
a restraining device that compresses and restrains the three or more stacked power storage devices toward the inside in the stacking direction,
The three or more power storage devices are electrically connected to each other in the stacking order of the power storage devices by the plurality of conductive connection members,
The three or more power storage devices arranged in a zigzag pattern in the case width direction,
the external electrode terminal portions are disposed at positions in the case width direction such that the external electrode terminal portions of adjacent power storage devices are aligned in the stacking direction,
The conductive connection member is
an electricity storage module extending in the stacking direction and connecting the external electrode terminals of adjacent electricity storage devices arranged in the stacking direction; an electrode assembly including an electrode laminated portion in which a plurality of electrode plates are laminated in an electrode plate lamination direction;
a case in which the electrode body is housed with the electrode plate lamination direction parallel to the case thickness direction; and
a plurality of electricity storage devices each having a pair of external electrode terminals fixed to a portion of one side of the case in a case height direction perpendicular to the case thickness direction,
the one side of each of the power storage devices in the case height direction is in the same direction,
The stacking direction is parallel to the thickness direction of the case, and
a plurality of electricity storage devices arranged in a zigzag pattern in a case width direction perpendicular to the case thickness direction and the case height direction;
a conductive connection member that connects the external electrode terminal portions of the power storage devices having different poles or the same pole that are adjacent to each other in the stacking direction;
a restraining device that compresses and restrains the stacked power storage devices toward an inner side in the stacking direction,
The plurality of power storage devices arranged in a zigzag pattern in the case width direction,
the pair of external electrode terminal portions are provided asymmetrically with respect to the width direction of the case,
the external electrode terminal portions are disposed at positions in the case width direction such that the external electrode terminal portions of adjacent power storage devices are aligned in the stacking direction,
The conductive connection member is
an electricity storage module extending in the stacking direction and connecting the external electrode terminals of adjacent electricity storage devices arranged in the stacking direction;

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