Power storage device

Abstract

To provide a power storage device which can protect power storage cells from both a load inputted to a case in the vertical direction and a load inputted to the case in a direction perpendicular to the vertical direction.SOLUTION: A power storage device 1 comprises: a plurality of power storage stacks 100; a case 200; and a protection structure 300 which protects a plurality of power storage cells 110 from a load inputted to the case 200. Each of the power storage stacks 100 has: a first unit stack 101; a second unit stack 102; and a middle plate 103. The case 200 has a bottom wall 212, a top wall 222, and peripheral walls 214, 224. A vertical length of the protection structure 300 is greater than a vertical length of the plurality of power storage cells 110. The protection structure 300 is disposed between a pair of the middle plates 103 adjacent to each other in the perpendicular direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an electricity storage device. [Background technology]

[0002] For example, Japanese Patent Application Laid-Open Publication No. 2020-155367 discloses a battery pack including multiple battery modules, a housing case that houses the battery modules, a plate disposed above the multiple battery modules, and multiple support members that support the plate. Each battery module includes multiple cells. The housing case has a lower case that opens upward and an upper case that opens downward. Each support member is disposed on the lower case. Multiple ribs are provided on the inner surface of the upper case. Each rib is provided from the inner surface of the upper case toward the plate. Each rib abuts against the plate. In this battery pack, when a downward load acts on the upper case, the load is transmitted to the lower case via the ribs, the plate, and the support members. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-155367 Summary of the Invention [Problem to be solved by the invention]

[0004] In the battery pack described in JP 2020-155367 A, it is desirable to be able to protect the storage cells not only from loads input to the case in the vertical direction, but also from loads input to the case in a direction perpendicular to the vertical direction.

[0005] An object of the present disclosure is to provide an energy storage device capable of protecting energy storage cells from both a load input to a case in the vertical direction and a load input in a direction perpendicular to the vertical direction. [Means for solving the problem]

[0006] An energy storage device according to one aspect of the present disclosure includes: a plurality of energy storage stacks each including a plurality of energy storage cells arranged to be lined up in one direction, and arranged to be lined up in an orthogonal direction that is orthogonal to both the one direction and a vertical direction; a case that houses the plurality of energy storage stacks; and a protective structure that is provided within the case and protects the plurality of energy storage cells from a load input to the case, wherein each energy storage stack of the plurality of energy storage stacks includes a first unit stack that is arranged on one side in the one direction and includes some energy storage cells of the plurality of energy storage cells; and a second unit stack that is arranged on the other side in the one direction and includes some energy storage cells of the plurality of energy storage cells. the case has a second unit stack including energy storage cells other than the energy storage cells included in the first unit stack, and an intermediate plate arranged between the first unit stack and the second unit stack, the case has a bottom wall arranged below the plurality of energy storage stacks, a top wall arranged above the plurality of energy storage stacks, and a peripheral wall connecting the peripheral edge of the bottom wall to the peripheral edge of the top wall and surrounding the plurality of energy storage stacks, the length of the protective structure in the vertical direction being greater than the length of the plurality of energy storage cells in the vertical direction, and the protective structure is arranged between a pair of the intermediate plates adjacent to each other in the orthogonal direction. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an energy storage device that can protect energy storage cells from both loads input to the case in the vertical direction and loads input in a direction perpendicular to the vertical direction. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view schematically illustrating a configuration of an electricity storage device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view schematically showing a state before the power storage stack is placed on the lower case. [Figure 3]FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a plan view schematically showing the positional relationship between a load transmitting member and an intermediate plate. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure will be described with reference to the accompanying drawings, in which the same or corresponding elements are designated by the same reference numerals.

[0010] 1 is a perspective view schematically illustrating the configuration of an electricity storage device according to an embodiment of the present disclosure. The electricity storage device 1 is mounted on, for example, a vehicle.

[0011] As shown in FIGS. 1 to 3, the electricity storage device 1 includes a plurality of electricity storage stacks 100, a case 200, a protective structure 300, a monitoring unit 410, and a wire harness 420.

[0012] As shown in Fig. 1, each power storage stack 100 has a plurality of power storage cells 110 arranged in one direction. An example of the power storage cells 110 is a lithium ion battery. Each power storage cell 110 is formed in a rectangular parallelepiped. As shown in Fig. 1, the plurality of power storage stacks 100 are arranged in an orthogonal direction that is orthogonal to both the one direction and the vertical direction.

[0013] Each power storage stack 100 has a first unit stack 101 , a second unit stack 102 , and an intermediate plate 103 .

[0014] The first unit stack 101 is arranged on one side in one direction. The first unit stack 101 includes some of the plurality of storage cells 110. The first unit stack 101 may include an end plate. The end plate is arranged outside the storage cell 110 arranged on the outermost side in one direction.

[0015] The second unit stack 102 is arranged on the other side in the one direction. The second unit stack 102 includes, among the plurality of energy storage cells 110, energy storage cells 110 other than the energy storage cells 110 included in the first unit stack 101. In the present embodiment, the number of energy storage cells 110 included in the second unit stack 102 is the same as the number of energy storage cells 110 included in the first unit stack 101. The second unit stack 102 may include end plates arranged outside the energy storage cells 110 in the one direction.

[0016] The intermediate plate 103 is disposed between the first unit stack 101 and the second unit stack 102. The intermediate plate 103 is disposed at the center of the electricity storage stack 100 in one direction. The intermediate plate 103 is made of synthetic resin or the like.

[0017] The case 200 houses a plurality of power storage stacks 100. The case 200 has a lower case 210 and an upper case 220 (see FIG. 3). Note that the upper case 220 is not shown in FIGS. 1 and 2.

[0018] The lower case 210 has a shape that opens upward. The lower case 210 is made of metal, synthetic resin, etc. The lower case 210 has a bottom wall 212, a lower surrounding wall 214, and a lower flange 216.

[0019] The bottom wall 212 is disposed below the plurality of power storage stacks 100. As shown in Fig. 2 and Fig. 3, a raised portion 212a that rises upward is formed in the center of the bottom wall 212 in one direction. The top of the raised portion 212a is formed flat. As shown in Fig. 3, the intermediate plate 103 is placed on the raised portion 212a.

[0020] A cooler (not shown) that cools the power storage stack 100 via the bottom wall 212 may be provided below the bottom wall 212. In this case, a heat conductive member (grease or the like) may be provided between the cooler and the bottom wall 212, or a heat conductive member may be provided between each power storage stack 100 and the bottom wall 212.

[0021] The lower surrounding wall 214 stands from the peripheral edge of the bottom wall 212 and surrounds the lower periphery of the multiple power storage stacks 100 .

[0022] The lower flange 216 has a shape that protrudes outward from the upper end of the lower surrounding wall 214 .

[0023] The upper case 220 has a shape that opens downward. The upper case 220, together with the lower case 210, houses a plurality of power storage stacks 100. The upper case 220 is made of metal, synthetic resin, or the like. The upper case 220 has a top wall 222, an upper surrounding wall 224, and an upper flange 226.

[0024] The top wall 222 is disposed above the plurality of power storage stacks 100. The top wall 222 may be formed in a flat plate shape. A gap is formed between the top wall 222 and each power storage stack 100.

[0025] The upper surrounding wall 224 extends downward from the peripheral edge of the top wall 222 and surrounds the periphery of the upper parts of the multiple power storage stacks 100. The upper surrounding wall 224 forms a peripheral wall together with the lower surrounding wall 214. The peripheral walls 214, 224 connect the peripheral edge of the bottom wall 212 and the peripheral edge of the top wall 222 and surround the periphery of the multiple power storage stacks 100.

[0026] The upper flange 226 has a shape that protrudes outward from the lower end of the upper surrounding wall 224. The upper flange 226 is fixed to the lower flange 216 with bolts or the like.

[0027] The protective structure 300 is provided in the case 200 and protects the plurality of energy storage cells 110 from a load input to the case 200. As shown in FIG. 3, the length of the protective structure 300 in the vertical direction is greater than the length of the plurality of energy storage cells 110 in the vertical direction. As shown in FIG. 4, the protective structure 300 is disposed between a pair of intermediate plates 103 adjacent to each other in the orthogonal direction. In this embodiment, the protective structure 300 has a cross member 310 and a load transfer member 320. Note that in FIG. 3, the first unit stack 101, the second unit stack 102, and the intermediate plates 103 are indicated by two-dot chain lines, and in FIG. 4, the first unit stack 101 and the second unit stack 102 are not shown.

[0028] The cross member 310 is disposed on the bottom wall 212. The cross member 310 has a shape that extends in one direction and is connected to the lower surrounding wall 214. In other words, the cross member 310 has a function of reinforcing the lower surrounding wall 214. The cross section of the cross member 310 in a plane perpendicular to the one direction is formed into a shape that is convex upward. The upper surface of the cross member 310 is preferably formed flat. The cross member 310 is disposed between a pair of power storage stacks 100 adjacent to each other in the perpendicular direction. In other words, the cross member 310 separates the pair of power storage stacks 100 adjacent to each other in the perpendicular direction.

[0029] The load transfer member 320 is disposed on the cross member 310. The load transfer member 320 transfers a load that is input downward relative to the top wall 222 to the cross member 310. The load transfer member 320 transfers a load that is input upward relative to the bottom wall 212 to the top wall 222. The load transfer member 320 is made of a synthetic resin or the like. As shown in FIG. 4, the load transfer member 320 is disposed between a pair of intermediate plates 103 that are adjacent to each other in the perpendicular direction.

[0030] The load transmission member 320 has a first pillar portion 321 , a second pillar portion 322 , and a connecting portion 323 .

[0031] The first pillar portion 321 is disposed on the cross member 310. The upper end of the first pillar portion 321 may be in contact with the top wall 222 or may be spaced apart from the top wall 222. The first pillar portion 321 has a first outer surface 321S formed on the outside in one direction. The first outer surface 321S has a shape that gradually moves away from the second pillar portion 322 as it approaches the cross member 310. A first connecting portion 321a is provided on the first outer surface 321S. The first connecting portion 321a has a shape that protrudes outward in one direction from the first outer surface 321S. A through-hole is provided in the first connecting portion 321a.

[0032] The second pillar portion 322 is disposed on the cross member 310. The second pillar portion 322 is disposed at a position spaced apart from the first pillar portion 321 in one direction. The upper end of the second pillar portion 322 may be in contact with the top wall 222, or may be spaced apart from the top wall 222. The second pillar portion 322 has a second outer surface 322S formed on the outside in one direction. The second outer surface 322S has a shape that gradually separates from the first pillar portion 321 as it approaches the cross member 310. A second connection portion 322a is provided on the second outer surface 322S.

[0033] The connecting portion 323 connects the first pillar portion 321 and the second pillar portion 322. As shown in Figs. 3 and 4, the connecting portion 323 is disposed between a pair of intermediate plates 103 that are adjacent to each other in the perpendicular direction. The connecting portion 323 may be in contact with the intermediate plate 103 or may be spaced apart from the intermediate plate 103. As shown in Fig. 3, the connecting portion 323 has an opposing surface 323S that faces the top wall 222 with a gap therebetween.

[0034] The connecting portion 323 is provided with a through hole 323h that passes through the connecting portion 323 in the perpendicular direction. A positioning member 325 may be provided inside this through hole 323h. The positioning member 325 engages with a pair of power storage stacks 100 that are adjacent to each other in the perpendicular direction with the load transmission member 320 sandwiched therebetween, thereby determining the positional relationship between these power storage stacks 100.

[0035] The monitoring unit 410 monitors the plurality of energy storage cells 110. As shown in FIG. 3, the monitoring unit 410 is disposed on the cross member 310 and adjacent to the load transfer member 320.

[0036] The wire harness 420 extends from the monitoring unit 410. As shown in Fig. 3, the wire harness 420 is disposed between the top wall 222 and the opposing surface 323S. The wire harness 420 is fixed to the first connecting portion 321a and the second connecting portion 322a by bolts or the like. The wire harness 420 may be fixed to the coupling portion 323.

[0037] As described above, in the energy storage device 1 of this embodiment, when a downward load is input to the top wall 222, the load is transmitted to the bottom wall 212 via the protective structure 300 (the first column section 321, the second column section 322, and the cross member 310), and conversely, when an upward load is input to the bottom wall 212, the load is transmitted to the top wall 222 via the protective structure 300. Therefore, the transmission of a load input in the vertical direction to the case 200 to the energy storage cells 110 is suppressed.

[0038] Furthermore, when a load is input in the orthogonal direction to a portion on one side of the peripheral walls 214, 224 in the orthogonal direction, the load is transmitted to a portion on the other side of the peripheral walls 214, 224 in the orthogonal direction via the intermediate plate 103 and the protective structure 300. This prevents the load input in the orthogonal direction to the peripheral walls from being transmitted to the energy storage cells.

[0039] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0040] The energy storage device in the above embodiment includes a plurality of energy storage stacks, each including a plurality of energy storage cells arranged to be lined up in one direction, and arranged to be lined up in an orthogonal direction that is orthogonal to both the one direction and a vertical direction; a case that houses the plurality of energy storage stacks; and a protective structure that is provided in the case and protects the plurality of energy storage cells from a load input to the case, and each energy storage stack of the plurality of energy storage stacks includes a first unit stack that is arranged on one side in the one direction and includes some energy storage cells of the plurality of energy storage cells, and a second unit stack that is arranged on the other side in the one direction and includes some energy storage cells of the front of the plurality of energy storage cells. the case has a second unit stack including energy storage cells other than the energy storage cells included in the first unit stack, and an intermediate plate arranged between the first unit stack and the second unit stack, the case has a bottom wall arranged below the plurality of energy storage stacks, a top wall arranged above the plurality of energy storage stacks, and a peripheral wall connecting a peripheral portion of the bottom wall to a peripheral portion of the top wall and surrounding the plurality of energy storage stacks, the length of the protective structure in the vertical direction being greater than the length of the plurality of energy storage cells in the vertical direction, and the protective structure is arranged between a pair of the intermediate plates adjacent to each other in the orthogonal direction.

[0041] In this energy storage device, when a downward load is applied to the top wall, the load is transmitted to the bottom wall via the protective structure, and when an upward load is applied to the bottom wall, the load is transmitted to the top wall via the protective structure, thereby preventing a load applied in the vertical direction to the case from being transmitted to the energy storage cells. Furthermore, when a load is applied in the orthogonal direction to one side of the peripheral wall in the orthogonal direction, the load is transmitted to the other side of the peripheral wall in the orthogonal direction via the intermediate plate and the protective structure, thereby preventing a load applied in the orthogonal direction to the peripheral wall from being transmitted to the energy storage cells.

[0042] The protective structure may further include a cross member disposed on the bottom wall between a pair of the power storage stacks adjacent to each other in the orthogonal direction, the cross member having a shape extending in the one direction and connected to the peripheral wall, and a load transfer member disposed on the cross member. The load transfer member is preferably disposed between the pair of the intermediate plates adjacent to each other in the orthogonal direction.

[0043] In this embodiment, the peripheral wall is reinforced by the cross member, and the load in the orthogonal direction is transmitted to the intermediate plate by the load transmission member.

[0044] The load transmitting member may have a first pillar portion, a second pillar portion disposed at a position spaced apart from the first pillar portion in the one direction, and a connecting portion connecting the first pillar portion and the second pillar portion. In this case, it is preferable that the connecting portion is disposed between a pair of the intermediate plates adjacent to each other in the orthogonal direction.

[0045] In this embodiment, the first pillar portion and the second pillar portion can transmit vertical loads at positions spaced apart in one direction, and further, because the first pillar portion and the second pillar portion are connected by a connecting portion, handling of the load transmission member becomes easier than when the first pillar portion and the second pillar portion are made of separate members.

[0046] The first pillar portion may have a first outer surface formed on the outside in the one direction, and the second pillar portion may have a second outer surface formed on the outside in the one direction. It is preferable that the first outer surface has a shape that gradually moves away from the second pillar portion as it approaches the cross member, and that the second outer surface has a shape that gradually moves away from the first pillar portion as it approaches the cross member.

[0047] In this embodiment, the resistance to a load input downward to the top wall is particularly increased. The energy storage device may further include a monitoring unit that monitors the plurality of energy storage cells, and a wire harness extending from the monitoring unit. In this case, it is preferable that the connecting portion has an opposing surface that faces the top wall with a gap therebetween, and the wire harness is disposed between the top wall and the opposing surface.

[0048] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0049] 1 Energy storage device, 100 Energy storage stack, 101 First unit stack, 102 Second unit stack, 103 Intermediate plate, 110 Energy storage cell, 200 Case, 210 Lower case, 212 Bottom wall, 212a Raised portion, 214 Lower surrounding wall, 216 Lower flange, 220 Upper case, 222 Top wall, 224 Upper surrounding wall, 226 Upper flange, 300 Protective structure, 310 Cross member, 320 Load transmission member, 321 First pillar portion, 321S First outer surface, 322 Second pillar portion, 322S Second outer surface, 323 Connection portion, 323S Opposing surface, 410 Monitoring unit, 420 Wire harness.

Claims

1. a plurality of power storage stacks each including a plurality of power storage cells arranged to be aligned in one direction and arranged to be aligned in an orthogonal direction that is orthogonal to both the one direction and the vertical direction; a case that houses the plurality of power storage stacks; a cross member provided in the case and disposed between a pair of the power storage stacks adjacent to each other in the orthogonal direction, Each of the plurality of power storage stacks includes: a first unit stack disposed on one side in the one direction and including some of the plurality of storage cells; a second unit stack that is disposed on the other side in the one direction and includes, among the plurality of power storage cells, power storage cells other than the power storage cells included in the first unit stack; an intermediate plate disposed between the first unit stack and the second unit stack, The case is a bottom wall disposed below the plurality of power storage stacks; a top wall disposed above the plurality of power storage stacks; a peripheral wall disposed to connect a peripheral edge portion of the bottom wall and a peripheral edge portion of the top wall, an interposition portion provided on the cross member and disposed between a pair of the intermediate plates adjacent to each other in the perpendicular direction; a first protruding portion provided on the cross member, disposed on one side of the interposed portion in the one direction, and protruding upward from upper surfaces of the plurality of energy storage cells; a second protruding portion that is provided on the cross member, is positioned on the other side of the interposition portion in the one direction, and protrudes upward from upper surfaces of the plurality of energy storage cells, The interposition portion has a through hole that connects a space on one side of the interposition portion to a space on the other side in the orthogonal direction.

2. The power storage device according to claim 1 , further comprising a conductive member arranged above the cross member on one side in the one direction of the first protrusion.

3. The power storage device according to claim 2 , further comprising a monitoring unit connected to the plurality of power storage cells using the conductive member.

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