Electricity storage device and vehicle

Abstract

A power storage device includes a first power storage stack and a second power storage stack arranged side by side in a first direction with a space therebetween, and a housing case provided with a case-side exhaust valve, the first power storage stack including a plurality of first unit cells arranged in a second direction orthogonal to the first direction, the second power storage stack including a plurality of second unit cells arranged in a third direction orthogonal to the first direction, and the housing case including a plurality of second unit cells arranged in a fourth direction orthogonal to the second direction. The second power storage stack includes a plurality of second unit cells arranged in the second direction, and each of the plurality of first unit cells is provided with a first exhaust valve capable of exhausting gas toward the opposite side from the side on which the second power storage stack is located. Each of the plurality of second unit cells is provided with a second exhaust valve capable of exhausting gas toward the opposite side of the side on which the first power storage stack is located.

Description

Technical Field

[0001] The present disclosure relates to a power storage device and a vehicle including the power storage device. Background Art

[0002] As a conventional power storage device, Japanese Patent Application Laid-Open No. 2019-192415 discloses a configuration in which power storage stacks are stacked adjacent to each other, each with exhaust valves provided on its side. In each power storage stack, the exhaust valves face the side of the housing. Summary of the Invention

[0003] In recent years, along with the increase in capacity, the length of storage batteries (unit cells) in the longitudinal direction has also become longer. In order to improve the efficiency of exhausting smoke from the storage batteries, it is considered to provide exhaust valves on both sides in the longitudinal direction. However, when a plurality of storage battery stacks having storage batteries arranged in a direction perpendicular to the longitudinal direction are arranged in the above-mentioned longitudinal direction, when the storage battery stack on one side of the adjacent storage battery stacks heats up, gas will be discharged from the storage battery on one side toward the storage battery stack on the other side. Similarly, when the storage battery stack on the other side heats up, gas will be discharged from the storage battery on the other side toward the storage battery stack on one side. In such a case, when any one of the adjacent storage battery stacks heats up, the adjacent storage battery stacks may also heat up each other.

[0004] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a power storage device and a vehicle that can suppress mutual heat generation between adjacent power storage stacks.

[0005] The power storage device according to the present disclosure includes: a first power storage stack and a second power storage stack; and a storage case for storing the first and second power storage stacks. The storage case is provided with a case-side exhaust valve capable of exhausting gas discharged into the storage case. The first power storage stack and the second power storage stack are arranged in a first direction with a gap therebetween. The first power storage stack includes a plurality of first cells arranged in a second direction orthogonal to the first direction. The second power storage stack includes a plurality of second cells arranged in the second direction. Each of the plurality of first cells is provided with a first exhaust valve capable of exhausting gas toward a side opposite to a side where the second power storage stack is located. Each of the plurality of second cells is provided with a second exhaust valve capable of exhausting gas toward a side opposite to a side where the first power storage stack is located.

[0006] With this configuration, gas from the first power storage stack is discharged toward the side opposite to the second power storage stack, and gas from the second power storage stack is discharged toward the side opposite to the first power storage stack. This prevents gas from being discharged from one of the first and second power storage stacks from being directed toward the other. As a result, even if one power storage stack generates heat, heating between the first and second power storage stacks can be prevented.

[0007] The power storage device according to the present disclosure may further include an electrical device housed within the housing and configured to control the first and second power storage stacks. The housing may include a first wall located on one side in the first direction and a second wall located on the other side in the first direction. The electrical device may include a first electrical device positioned in a gap between the first wall and the first power storage stack, and a second electrical device positioned in a gap between the second wall and the second power storage stack.

[0008] With this configuration, the first electrical device is positioned between the first power storage stack and the first wall, significantly increasing the available space. Similarly, the second electrical device is positioned between the second power storage stack and the second wall, significantly increasing the available space. By utilizing this space as an exhaust path, the space within the storage case can be effectively utilized.

[0009] In addition, since the space inside the storage shell can be used as an exhaust path, the reduction in the rigidity of the storage shell can be suppressed compared to a structure in which multiple through holes connected to the multiple first exhaust valves and the multiple second exhaust valves are respectively provided on each wall portion of the storage shell opposite to the multiple first exhaust valves and the multiple second exhaust valves.

[0010] In the power storage device according to the present disclosure, the case-side exhaust valve may be provided on each of the first wall portion and the second wall portion.

[0011] According to the above configuration, the gas discharged from the first electricity storage stack and the second electricity storage stack into the storage case can be efficiently discharged to the outside of the storage case.

[0012] The power storage device according to the present disclosure may further include an electrical device housed within the housing and configured to control the first and second power storage stacks. The housing may include a first wall located on one side in the first direction, a second wall located on the other side in the first direction, and a pair of side walls connecting the first and second walls. The electrical device may be positioned between the first wall and the first power storage stack. The housing-side exhaust valve may be disposed on the first wall. An exhaust path to the housing-side exhaust valve may be provided within at least one of the first wall, the second wall, and the pair of side walls.

[0013] According to the above configuration, gas exhausted from the first electricity storage stack can be exhausted from the first wall, and gas exhausted from the second electricity storage stack can be exhausted from the first wall through the inner side of the wall of the storage case.

[0014] In the power storage device according to the present disclosure, a first connector electrically connected to the first power storage stack and a second connector electrically connected to the second power storage stack may be provided on one side of the first wall portion in the second direction. The case-side exhaust valve provided on the first wall portion may be provided on the other side of the first wall portion in the second direction.

[0015] According to the above configuration, since the gas flows toward the side opposite to the side where the first connector and the second connector are located, it is possible to suppress the first connector and the second connector from being damaged by heat.

[0016] A vehicle according to the present disclosure includes the above-described power storage device and a vehicle body (vehicle body) to which the above-described power storage device is fixed.

[0017] According to the above configuration, by providing the above power storage device, it is possible to suppress the mutual generation of heat between the first power storage stack and the second power storage stack in the vehicle.

[0018] The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram showing a vehicle equipped with the power storage device according to the first embodiment.

[0020] Figure 2 This is a diagram showing a state in which the power storage device according to the first embodiment is fixed to a vehicle.

[0021] Figure 3 This is a schematic exploded perspective view of the power storage device according to the first embodiment.

[0022] Figure 4 This is a schematic plan view showing how gas moves when a predetermined unit cell generates heat in the power storage device according to the first embodiment.

[0023] Figure 5 This is a schematic plan view showing how gas moves when a predetermined unit cell generates heat in the power storage device according to the second embodiment. DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the embodiments described below, identical or common parts will be denoted by identical reference numerals in the drawings, and their description will not be repeated.

[0025] (Implementation Method 1)

[0026] Figure 1 This is a schematic diagram showing a vehicle equipped with the power storage device according to the first embodiment. Figure 2 1 is a diagram showing a state where the power storage device according to the first embodiment is fixed to a vehicle. Figure 1 and Figure 2 , vehicle 1 according to embodiment 1 will be described.

[0027] The vehicle 1 is a hybrid vehicle that can travel using power from at least one of a motor and an engine, or an electric vehicle that travels using driving force obtained from electric energy.

[0028] Vehicle 1 includes a vehicle body 2, front wheels 3, rear wheels 4, and an electrical storage device 10. Vehicle body 2 includes a frame member 5. Electrical storage device 10 is disposed below vehicle body 2. For example, electrical storage device 10 is disposed between front wheels 3 and rear wheels 4. Alternatively, a portion of electrical storage device 10 may be disposed so as to overlap at least one of front wheels 3 and rear wheels 4 when viewed in the width direction of vehicle 1. Electrical storage device 10 has an upper surface 10a. This upper surface 10a can function as a floor member defining the interior of the vehicle.

[0029] The frame member 5 includes a pair of side members 6 and a pair of side sills 7. The pair of side sills 7 are arranged at both ends in the width direction of the vehicle 1. The pair of side members 6 are arranged inside the pair of side sills 7 at a distance. The pair of side members 6 and the pair of side sills 7 extend in the front-rear direction of the vehicle 1.

[0030] The pair of longitudinal beams 6 are spaced apart in the width direction of the vehicle 1. The main body 35 of the power storage device 10 is disposed in the gap between the pair of longitudinal beams 6. A gap is provided between the main body 35 and the pair of longitudinal beams 6. This prevents the power storage device 10 from receiving an impact even in the event of a side collision of the vehicle 1.

[0031] Fixed portions 36 are provided on both side surfaces of the main body portion 35 in the width direction of the vehicle 1. The fixed portions 36 are fixed to the pair of side members 6 by fastening members 8.

[0032] The frame member 5 further includes a transverse frame member 9 . The transverse frame member 9 is provided above the power storage device 10 so as to span from one door sill 7 to the other door sill 7 . The upper surface 10 a of the power storage device 10 is fixed to the transverse frame member 9 .

[0033] In the above description, the framework member 5 is described as including a pair of longitudinal beams 6 and a pair of door sills 7, but the present invention is not limited thereto. The pair of door sills 7 may also function as the pair of longitudinal beams 6. In this case, the pair of longitudinal beams 6 can be omitted, and the fixed portion 36 may be fixed to the pair of door sills 7.

[0034] Figure 3 This is a schematic exploded perspective view of the power storage device according to the first embodiment. Figure 3 , the detailed structure of the power storage device 10 will be described.

[0035] The power storage device 10 includes a plurality of power storage modules 20 , a housing case 30 , case-side exhaust valves 41 and 42 , and first and second electrical devices 71 and 72 .

[0036] The plurality of power storage modules 20 are arranged in a first direction (DR1). When the power storage device 10 is mounted on the vehicle 1, the first direction is parallel to, for example, the front-rear direction of the vehicle 1. The plurality of power storage modules 20 include a first power storage stack 21 and a second power storage stack 22. The first power storage stack 21 and the second power storage stack 22 are arranged in the first direction with a gap therebetween.

[0037] The first power storage stack 21 includes a plurality of first cells 211. The plurality of first cells 211 are arranged in a second direction (DR2 direction) perpendicular to the first direction. The second direction is parallel to the left-right direction of the vehicle 1 in the mounted state.

[0038] Each first cell 211 is provided with a first exhaust valve 215. The first exhaust valve 215 is configured to exhaust gas toward the side opposite to the side where the second power storage stack 22 is located. The first exhaust valve 215 is provided on the side surface of the first cell 211 located on one side in the first direction. The first exhaust valve 215 is used to discharge exhaust gas from the first cell 211 when the pressure within the first cell 211 exceeds a predetermined pressure.

[0039] The second power storage stack 22 includes a plurality of second cells 221. The plurality of second cells 221 are arranged in the second direction. A second exhaust valve 225 is provided in each second cell 221. The second exhaust valve 225 is configured to exhaust gas toward the side opposite to the side where the first power storage stack 21 is located. The second exhaust valve 225 is provided on the side of the second cell 221 located on the other side in the first direction. The second exhaust valve 225 is a valve for discharging exhaust gas from the second cell 221 when the pressure within the second cell 221 exceeds a predetermined pressure.

[0040] The first unit cell 211 and the second unit cell 221 have a long shape with the first direction as the longitudinal direction. The first unit cell 211 and the second unit cell 221 have a flat rectangular parallelepiped shape with a thickness in the second direction.

[0041] The first unit cell 211 and the second unit cell 221 can be made of the same storage battery. In this case, the number of components can be reduced, thereby lowering manufacturing costs. Furthermore, "same" also means "including manufacturing errors such as tolerances." Alternatively, the first unit cell 211 and the second unit cell 221 can be made of different storage batteries.

[0042] The first unit cell 211 and the second unit cell 221 include a casing, and a single or a plurality of electrode bodies are housed inside the casing.

[0043] When a single electrode body is housed in the housing, the electrode body has a shape extending in the aforementioned longitudinal direction. The electrode body may be a stacked electrode body formed by stacking a negative electrode sheet, a separator, and a positive electrode sheet, or a wound electrode body formed by winding a negative electrode sheet, a separator, and a positive electrode sheet.

[0044] When a plurality of electrode bodies are housed in the housing, the plurality of electrode bodies are arranged in a longitudinal direction and connected in series. In this case as well, the electrode body may be a stacked electrode body or a wound electrode body.

[0045] The first cell 211 and the second cell 221 are secondary batteries such as nickel-metal hydride batteries or lithium-ion batteries. Liquid or solid electrolytes may be used in the first cell 211 and the second cell 221. The first cell 211 and the second cell 221 may also be chargeable and dischargeable capacitors.

[0046] The storage case 30 includes an upper member 31 and a lower member 32 serving as a lower case. The lower member 32 has a substantially box-like shape that is open upward. The lower member 32 includes a main body portion 35 and a fixed portion 36.

[0047] The main body 35 includes a bottom wall 321 , a first wall 322 , a second wall 323 , and a pair of side walls 324 , 325 . The first wall 322 , the second wall 323 , and the pair of side walls 324 , 325 are provided so as to stand from the peripheral edge of the bottom wall 321 .

[0048] The first wall portion 322 and the second wall portion 323 are opposed to each other in the first direction. The first wall portion 322 is located on one side in the first direction. The second wall portion 323 is located on the other side in the first direction. A pair of side walls 324 and 325 are opposed to each other in the second direction. The pair of side walls 324 and 325 connect the first wall portion 322 and the second wall portion 323. The side wall portion 324 connects the ends of the first wall portion 322 and the second wall portion 323 located on one side in the second direction. The side wall portion 325 connects the ends of the first wall portion 322 and the second wall portion 323 located on the other side in the second direction.

[0049] The fixed portion 36 is provided on the outer surfaces of the pair of side walls 324 and 325. The fixed portion 36 is provided to extend intermittently in the first direction. The portion of the fixed portion 36 located closest to the first direction is longer than the other portions in the first direction.

[0050] The housing-side exhaust valves 41 and 42 function as pressure relief valves, discharging gas from the storage housing 30 to the exterior of the storage housing 30 when the pressure within the storage housing 30 exceeds a predetermined pressure. The housing-side exhaust valve 41 is disposed on the first wall portion 322. The housing-side exhaust valve 42 is disposed on the second wall portion 323. The housing-side exhaust valves 41 and 42 are disposed at opposite corners, for example, when viewed from above. More specifically, the housing-side exhaust valve 42 is disposed on one side of the second wall portion 323 in the second direction, while the housing-side exhaust valve 41 is disposed on the other side of the first wall portion 322 in the second direction.

[0051] The first electrical device 71 is disposed between the first wall 322 and the first power storage stack 21. The second electrical device 72 is disposed between the second wall 323 and the second power storage stack 22. The first electrical device 71 and the second electrical device 72 are, for example, a battery ECU for controlling the power storage module, a junction box including relays for enabling and disabling charging and discharging of the battery pack with the outside world, and the like.

[0052] Figure 4 This is a schematic plan view showing how gas moves when a predetermined unit cell generates heat in the power storage device according to the first embodiment. Figure 4 The movement of the gas generated from the first electricity storage stack 21 and the movement of the gas generated from the second electricity storage stack 22 will be described.

[0053] like Figure 4As shown, a first connector 81 and a second connector 82 are provided on the first wall portion 322. The first power storage stack 21 and the second power storage stack 22 are electrically connected in series, with the first connector 81 being electrically connected to the first external terminal (positive electrode terminal) of the first power storage stack 21. The second connector 82 is connected to the second external terminal (negative electrode terminal) of the second power storage stack 22 via a wiring 83.

[0054] The first connector 81 and the second connector 82 are located on one side of the first wall portion 322 in the second direction, and the case-side exhaust valve 41 is located on the other side of the first wall portion 322 in the second direction. The position of the case-side exhaust valve 41 is not limited to the position described above; it can be located on the first wall portion 322 and can be set as appropriate. The case-side exhaust valve 42 is located on one side of the second wall portion 323 in the second direction. The case-side exhaust valve 42 is located on the side opposite to the connection portion connecting the wiring 83 to the second power storage stack 22 in the second direction. The position of the case-side exhaust valve 42 is not limited to the position described above; it can be located on the second wall portion 323 and can be set as appropriate.

[0055] When gas G1 is discharged from a predetermined first unit cell 211 of the first power storage stack 21 , the case-side exhaust valve 41 is provided on the side opposite to the side where the second power storage stack 22 is located as described above, so that the gas G1 is discharged toward the side opposite to the side where the second power storage stack 22 is located.

[0056] Similarly, when gas G2 is discharged from a predetermined second unit cell 221 of the second power storage stack 22, by arranging the case-side exhaust valve 42 on the side opposite to the side where the first power storage stack 21 is located as described above, the gas G2 is discharged toward the side opposite to the side where the first power storage stack 21 is located.

[0057] When gas is discharged from one of the first and second power storage stacks 21 and 22, it is possible to prevent the discharged gas from traveling toward the other power storage stack. Consequently, even if one power storage stack generates heat, it is possible to prevent the first and second power storage stacks 21 and 22 from generating heat together.

[0058] Here, gas G1 from the first power storage stack 21 is exhausted toward the first electrical device 71. The space between the first power storage stack 21 and the first wall 322, where the first electrical device 71 is located, is significantly expanded. Gas G1 is exhausted toward this space and then discharged outside the housing case 30 through the case-side exhaust valve 41 provided on the first wall 322.

[0059] Similarly, gas G2 from the second power storage stack 22 is exhausted toward the second electrical device 72. The space between the second power storage stack 22 and the second wall 323, where the second electrical device 72 is located, is significantly expanded. Gas G2 is exhausted into this space and then discharged outside the housing case 30 through the case-side exhaust valve 42 provided on the second wall 323.

[0060] By utilizing the considerably expanded space within the storage case 30 as an exhaust path, it is possible to effectively utilize the space within the storage case 30 while suppressing gas from one power storage stack from flowing toward the other power storage stack.

[0061] Furthermore, by providing the case-side exhaust valve 41 on the first wall portion 322 and the case-side exhaust valve 42 on the second wall portion 323 , gas exhausted from the first power storage stack 21 or the second power storage stack 22 into the storage case 30 can be efficiently exhausted to the outside of the storage case 30 .

[0062] Moreover, since the space inside the storage shell 30 can be used as an exhaust path, the reduction in the rigidity of the storage shell 30 can be suppressed compared to a structure in which multiple through holes respectively connected to the multiple first exhaust valves 215 and the multiple second exhaust valves 225 are provided on the first wall portion 322 opposite to the multiple first exhaust valves 215 and the second wall portion 323 of the storage shell opposite to the multiple second exhaust valves 225.

[0063] In addition, the shell side exhaust valve 41 is arranged in the second direction on the opposite side of the side where the first connector 81 and the second connector 82 are located, whereby the gas G1 is directed toward the opposite side of the side where the first connector 81 and the second connector 82 are located, thereby preventing the first connector 81 and the second connector 82 from being damaged by heat.

[0064] Similarly, the case-side exhaust valve 42 is provided in the second direction on the side opposite to the connection portion between the wiring 83 and the second power storage stack 22 . This allows the gas G2 to flow toward the side opposite to the connection portion, thereby preventing the connection portion from being damaged by heat.

[0065] (Implementation Method 2)

[0066] Figure 5 This is a schematic plan view showing how gas moves when a predetermined unit cell generates heat in the power storage device according to the second embodiment. Figure 5 , power storage device 10A according to Embodiment 2 will be described.

[0067] like Figure 5As shown, the power storage device 10A of the second embodiment differs from the power storage device 10 of the first embodiment in that the second electrical device 72 is not provided, the case-side exhaust valve 42 is not provided on the second wall portion 323, and the exhaust path of the gas G2 originating from the second power storage stack 22 is not provided. The remaining configuration is substantially the same.

[0068] In the power storage device 10A, the first electric device 71 is disposed between the first wall 322 and the first power storage stack 21 , and no electric device is disposed between the second wall 323 and the second power storage stack 22 .

[0069] Furthermore, an inlet port 323h for introducing gas G2 is provided on the inner surface of the second wall portion 323. The inlet port 323h is provided on the side opposite to the connection portion connecting the wiring 83 to the second power storage stack 22 in the second direction. An exhaust path from the inlet port 323h to the case-side exhaust valve 41 is provided within the second wall portion 323 of the storage case 30, within the first wall portion 322, and within at least one of the pair of side walls 324 and 325.

[0070] When gas G1 is discharged from a predetermined first unit cell 211 of the first power storage stack 21 , the gas G1 is discharged toward the space where the first electrical device 71 is arranged, and the space functions as a part of the exhaust path, and the gas G1 is discharged from the case-side exhaust valve 41 , as in the first embodiment.

[0071] On the other hand, when the gas G2 is discharged from the predetermined second unit cell 221 of the second power storage stack 22, the gas G2 discharged toward the side opposite to the side where the first power storage stack 21 is located is introduced into the interior of the second wall portion 323 through the inlet port 323h, and is discharged to the outside of the storage case 30 from the case-side exhaust valve 41 through the above-mentioned exhaust path provided in the wall portion of the storage case 30.

[0072] Even with the above configuration, power storage device 10A according to the second embodiment can achieve substantially the same effects as power storage device 10 according to the first embodiment. In particular, even when there is no space for arranging second electrical equipment 72 on the second wall portion 323 side, the above configuration allows gas G2 exhausted from second power storage stack 22 to pass through the inner wall of housing case 30 and be exhausted from first wall portion 322 side. This prevents gas G2 exhausted from second power storage stack 22 from directly traveling toward first power storage stack 21, and prevents the gas G2 from causing a temperature increase in first power storage stack 21.

[0073] While the embodiments of the present invention have been described, the embodiments disclosed herein are to be construed as illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims, and is intended to encompass all modifications within the meaning and scope of the claims and equivalents thereof.

Claims

1. A power storage device comprising: a first electricity storage stack and a second electricity storage stack; and a housing case for housing the first electricity storage stack and the second electricity storage stack, The housing case is provided with a housing-side exhaust valve capable of exhausting the gas exhausted into the housing case. The first electricity storage stack and the second electricity storage stack are arranged side by side with a gap therebetween in a first direction. The first electricity storage stack includes a plurality of first unit cells arranged in a second direction perpendicular to the first direction. The second electricity storage stack includes a plurality of second unit cells arranged in the second direction. Each of the plurality of first cells is provided with a first exhaust valve capable of exhausting gas toward a side opposite to the side where the second electricity storage stack is located. Each of the plurality of second unit cells is provided with a second exhaust valve capable of exhausting gas toward a side opposite to a side where the first electricity storage stack is located.

2. The power storage device according to claim 1, The power storage device further includes an electrical device, which is housed in the housing case and is used to control the first power storage stack and the second power storage stack. The storage case includes a first wall portion located on one side in the first direction and a second wall portion located on the other side in the first direction. The electric device includes a first electric device disposed in a gap between the first wall and the first electricity storage stack, and a second electric device disposed in a gap between the second wall and the second electricity storage stack.

3. The power storage device according to claim 2, The case-side exhaust valve is provided on each of the first wall portion and the second wall portion.

4. The power storage device according to claim 1, The power storage device further includes an electrical device, which is housed in the housing case and is used to control the first power storage stack and the second power storage stack. The storage case includes a first wall portion located on one side in the first direction, a second wall portion located on the other side in the first direction, and a pair of side walls connecting the first wall portion and the second wall portion. The electrical device is arranged between the first wall portion and the first electricity storage stack. The housing side exhaust valve is provided on the first wall portion, An exhaust path to the case-side exhaust valve is provided inside at least one of the first wall portion, the second wall portion, and the pair of side walls.

5. The power storage device according to any one of claims 2 to 4, A first connector electrically connected to the first power storage stack and a second connector electrically connected to the second power storage stack are provided on one side of the first wall portion in the second direction. The casing-side exhaust valve provided on the first wall portion is provided on the other side of the first wall portion in the second direction.

6. A vehicle comprising: The power storage device according to any one of claims 1 to 4; and A vehicle body is provided to which the power storage device is fixed.

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