Power storage device

Abstract

To provide a power storage device capable of suppressing short circuits between the total positive terminal and the total negative terminal.SOLUTION: A power storage device 10 includes one or more storage stacks and is equipped with a storage module 20 having a total positive terminal 15 and a total negative terminal 16, a storage case that houses the storage module 20, a case-side exhaust valve 42 provided in the storage case, a first connector 81 electrically connected to the total positive terminal 15 and a second connector 82 electrically connected to the total negative terminal 16, the storage case has a first wall portion 322 and a second wall portion 323 facing each other in a first direction, the first connector 81 and the second connector 82 are provided on the first wall portion 322, the case-side exhaust valve 42 is provided on the second wall portion 323, and each of the one or more storage stacks is configured to be able to exhaust gas in a second direction perpendicular to the first direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] As a conventional power storage device, International Publication No. 2020 / 134054 (Patent Document 1) discloses a configuration in which a plurality of power storage stacks are arranged in a predetermined direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 134054 Summary of the Invention [Problem to be solved by the invention]

[0004] The plurality of power storage stacks are electrically connected in series, and the power storage device includes a total positive terminal and a total negative terminal for the total potential of the plurality of power storage stacks. In general, a first connector electrically connected to the total positive terminal and a second connector electrically connected to the total negative terminal are provided on the same wall of the housing case.

[0005] If no measures are taken, when gas is discharged from one of the power storage stacks, debris contained in the gas may electrically connect and short-circuit the first connector and the second connector, or electrically connect and short-circuit a portion of the electrical path from the total positive terminal to the first connector that is routed near the first connector with a portion of the electrical path from the total negative terminal to the second connector that is routed near the second connector. In other words, a short-circuit between the total negative terminal and the total positive terminal may occur via the first connector and the second connector and / or the electrical path. In such a case, there is a concern that the multiple power storage stacks that make up the power storage module may generate heat overall.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and an object of the present disclosure is to provide an energy storage device that can suppress short-circuiting between the total positive terminal and the total negative terminal. [Means for solving the problem]

[0007] An energy storage device according to the present disclosure includes an energy storage module including one or more energy storage stacks and having a total positive terminal and a total negative terminal, a housing case that houses the energy storage module, a case-side exhaust valve provided in the housing case, a first connector electrically connected to the total positive terminal, and a second connector electrically connected to the total negative terminal. The housing case has a first wall portion and a second wall portion that face each other in a first direction. The first connector and the second connector are provided in the first wall portion. The case-side exhaust valve is provided in the second wall portion. Each of the one or more energy storage stacks is configured to be able to exhaust gas in a second direction perpendicular to the first direction.

[0008] According to the above configuration, the case-side exhaust valve is provided on the opposite side of the first direction from the side where the first connector and the second connector are located, and gas is discharged from the power storage stack in a second direction perpendicular to the first direction. This prevents gas discharged from the power storage stack from heading toward the first connector and the second connector. This prevents short-circuiting between the first connector and the second connector, which may be contained in the gas, and between a portion of the electrical path from the positive terminal to the first connector that is routed near the first connector and a portion of the electrical path from the negative terminal to the second connector that is routed near the second connector. This prevents short-circuiting between the positive terminal and the negative terminal.

[0009] In the power storage device according to the present disclosure, the gas discharged from any one of the one or more power storage stacks may be discharged from the case-side exhaust valve through a space within the accommodating case.

[0010] According to the above configuration, the space inside the storage case can be used as a gas exhaust path, so that the configuration of the storage case can be simplified.

[0011] In the power storage device according to the present disclosure, the storage case includes a third wall and a fourth wall that connect both end portions of the first wall and the second wall in the second direction, respectively. In this case, at least one of the third wall and the fourth wall may be provided with an inlet through which the gas is introduced and a flow path that connects the inlet and the case-side exhaust valve.

[0012] According to the above configuration, a smoke exhaust path is provided on the outer wall of the housing case, which makes it possible to suppress accumulation of debris contained in the gas within the housing space of the housing case and to suppress short circuits in the power storage stack caused by the debris. [Effects of the Invention]

[0013] According to the present disclosure, it is possible to provide an electricity storage device that can prevent a short circuit between the total positive terminal and the total negative terminal. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram showing a vehicle equipped with a power storage device according to a first embodiment. [Figure 2] 2 is a diagram showing a state in which the electricity storage device according to the first embodiment is fixed to a vehicle body. FIG. [Figure 3] FIG. 2 is an exploded perspective view of the electricity storage device according to the first embodiment. [Figure 4] 5 is a diagram illustrating the flow of gas discharged from the power storage stack in the power storage device according to the first embodiment. FIG. [Figure 5] 10 is a diagram illustrating the flow of gas discharged from the power storage stack in the power storage device according to the second embodiment. FIG. [Figure 6] FIG. 11 is a cross-sectional view of an electricity storage device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0016] (Embodiment 1) Fig. 1 is a schematic diagram showing a vehicle according to embodiment 1. Fig. 2 is a diagram showing a state in which an electricity storage device according to embodiment 1 is fixed to a vehicle body. Vehicle 1 according to the embodiment will be described with reference to Figs. 1 and 2.

[0017] The vehicle 1 is a hybrid vehicle that can run using at least one of the power of a motor and an engine, or an electric vehicle that runs using driving force obtained from electrical energy.

[0018] The vehicle 1 includes a vehicle body 2, front wheels 3, rear wheels 4, and a power storage device 10. The vehicle body 2 includes a frame member 5. The power storage device 10 is disposed below the vehicle body 2. The power storage device 10 is disposed, for example, between the front wheels 3 and the rear wheels 4. Note that a portion of the power storage device 10 may be disposed overlapping at least one of the front wheels 3 and the rear wheels 4 when viewed from the width direction of the vehicle 1. The power storage device 10 has an upper surface 10a. The upper surface 10a may function as a floor member that defines the interior of the vehicle cabin.

[0019] The framework member 5 includes a pair of side members 6 and a pair of side sills 7. The pair of side sills 7 are arranged on both ends of the vehicle 1 in the width direction. The pair of side members 6 are arranged at a distance inside the pair of side sills 7. The pair of side members 6 and the pair of side sills 7 extend along the front-rear direction of the vehicle 1.

[0020] The pair of side members 6 are spaced apart in the width direction of the vehicle 1. A main body 35 of the electricity storage device 10 is disposed in the gap between the pair of side members 6. A gap is provided between the main body 35 and the pair of side members 6. This makes it possible to suppress input of an impact to the electricity storage device 10 even in the event of a side collision of the vehicle 1.

[0021] 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.

[0022] The framework member 5 also includes a cross framework member 9. The cross framework member 9 is provided above the electricity storage device 10 so as to straddle from one side sill 7 to the other side sill 7. To the cross framework member 9, an upper surface 10a of the electricity storage device 10 is fixed.

[0023] In the above description, the framework member 5 includes a pair of side members 6 and a pair of side sills 7, but is not limited to this. The pair of side sills 7 may also function as the pair of side members 6. In this case, the pair of side members 6 can be omitted, and the above-mentioned fixed portion 36 may be fixed to the pair of side sills 7.

[0024] 3 is an exploded perspective view of the power storage device according to Embodiment 1. With reference to FIG. 3, the power storage device 10 according to Embodiment 1 will be described.

[0025] As shown in FIG. 3, the electricity storage device 10 includes an electricity storage module 20, a housing case 30, a case-side exhaust valve 42, an electrical connection member 50, and a cross member 70.

[0026] The power storage module 20 includes 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 a first direction (DR1 direction). Note that the first direction is, for example, parallel to the front-rear direction of the vehicle 1.

[0027] Each of the first power storage stack 21 and the second power storage stack includes a plurality of unit cells 210. The plurality of unit cells 210 are arranged in a first direction. More specifically, the plurality of unit cells 210 are arranged in the first direction with exhaust valves 215 (described later) positioned on one side in the second direction.

[0028] The unit cell 210 has a longitudinal shape with a second direction perpendicular to the first direction as its longitudinal direction, and has a flat rectangular parallelepiped shape with a thickness in the first direction.

[0029] Each of the plurality of unit cells 210 has a housing 211 , an exhaust valve 215 , a positive electrode external terminal 217 , and a negative electrode external terminal 218 .

[0030] The housing 211 has a pair of side walls facing each other in the longitudinal direction. The exhaust valve 215 is provided on one of the pair of side walls. The exhaust valve 215 is a valve for discharging gas from the unit cell 210 when the pressure inside the unit cell 210 exceeds a predetermined pressure. The exhaust valve 215 may be provided on the other of the pair of side walls, or on both of the pair of side walls.

[0031] The positive external terminal 217 and the negative external terminal 218 are provided, for example, on the upper wall portions of the casings 211, 221. The positive external terminal 217 and the negative external terminal 218 may also be provided on the side wall portions of the casing 211 in the longitudinal direction.

[0032] One or more electrode bodies 25 are housed inside the housing 211. When a single electrode body 25 is housed, the electrode body 25 has a shape extending in the longitudinal direction. The electrode body 25 may be a laminated electrode body in which a negative electrode sheet, a separator, and a positive electrode sheet are laminated, or may be a wound electrode body in which a negative electrode sheet, a separator, and a positive electrode sheet are wound.

[0033] When multiple electrode bodies 25 are housed, the multiple electrode bodies 25 are arranged side by side in the longitudinal direction and connected in series. In this case, too, the electrode body 25 may be a laminated electrode body or a wound electrode body.

[0034] The unit cell 210 is a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The unit cell 210 may use a liquid electrolyte or a solid electrolyte. The unit cell 210 may also be a chargeable and dischargeable capacitor.

[0035] The housing case 30 includes an upper member 31 and a lower member 32 serving as a lower case. The lower member 32 has a generally box-like shape that opens upward. The lower member 32 includes a main body portion 35 and a fixed portion 36.

[0036] The main body 35 has a bottom wall 321, a first wall 322, a second wall 323, and a pair of side walls 324 and 325. The first wall 322, the second wall 323, and the pair of side walls 324 and 325 are provided to stand upright from the periphery of the bottom wall 321.

[0037] The first wall portion 322 and the second wall portion 323 face 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. The pair of side walls 324, 325 face each other in the second direction. The side wall portion 324 is a third wall portion and is located on one side in the second direction. The side wall portion 325 is a fourth wall portion and is located on the other side in the second direction.

[0038] 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.

[0039] The fixed portion 36 is provided on the outer surfaces of the pair of side wall portions 324, 325. The fixed portion 36 is provided so as to extend discontinuously in the first direction. The portion of the fixed portion 36 located furthest to one side in the first direction is longer in the first direction than the other portions.

[0040] The upper member 31 has a generally plate-like shape. The upper member 31 closes the opening of the lower member 32. The shape of the upper member is not limited to a plate-like shape, and may be a generally box-like shape that opens downward. The upper member 31 has a top plate portion that faces the bottom wall portion 321 in the vertical direction.

[0041] The case-side exhaust valve 42 is provided in the storage case. Specifically, it is provided in the second wall portion 323. The case-side exhaust valve 42 is a pressure relief valve that opens when the pressure inside the storage case 30 exceeds a predetermined pressure. When the pressure inside the storage case 30 exceeds the predetermined pressure due to gas discharged from the first power storage stack 21 or the second power storage stack 22, the case-side exhaust valve 42 opens and the gas is discharged to the outside of the storage case 30.

[0042] The electrical connection member 50 electrically connects the first power storage stack 21 and the second power storage stack 22. The electrical connection member 50 is formed of a conductive member such as a bus bar. The electrical connection member 50 is arranged so as to straddle the cross member 70. This makes it possible to prevent interference between the electrical connection member 50 and the cross member 70.

[0043] The cross member 70 is disposed between the first power storage stack 21 and the second power storage stack 22 in the accommodation case 30. The cross member 70 extends in a direction intersecting the arrangement direction in which the first power storage stack 21 and the second power storage stack 22 are arranged. Specifically, the cross member 70 extends in a second direction that is perpendicular to the first direction. A gap is formed between the cross member 70 and the upper member 31.

[0044] In the present embodiment, a gap is provided between the cross member 70 and the pair of side wall portions 324, 325. An accommodation space located on one side of the cross member 70 in the first direction and in which the first power storage stack 21 is disposed is connected to an accommodation space located on the other side of the cross member 70 in the first direction and in which the second power storage stack 22 is disposed via the gap.

[0045] FIG. 4 is a diagram illustrating the flow of gas discharged from the power storage stack in the power storage device according to the first embodiment.

[0046] 4, the power storage device 10 includes a first connector 81, a second connector 82, and wiring 83 and 84. The first connector 81 and the second connector 82 are provided on the first wall portion 322. The first connector 81 and the second connector 82 are arranged side by side in the second direction.

[0047] The energy storage module 20 includes a total positive terminal 15 and a total negative terminal 16 for the total potential. The total positive terminal 15 is formed, for example, by a positive electrode external terminal 217 of the unit cell 210 located on the most one side in the first direction in the first energy storage stack 21. The total negative terminal 16 is formed, for example, by a negative electrode external terminal 218 of the unit cell 210 located on the most other side in the first direction in the second energy storage stack 22.

[0048] The first connector 81 is connected to the positive terminal 15 by a wire 83. The second connector 82 is connected to the negative terminal 16 by a wire 84.

[0049] Each of the first power storage stack 21 and the second power storage stack 22 is provided so as to be able to discharge gas in the second direction. Specifically, in each of the first power storage stack 21 and the second power storage stack 22, the exhaust valve 215 is arranged so as to be located on one side in the second direction, as described above.

[0050] For example, when gas G is discharged from any of the unit cells 210 of the first power storage stack 21, the gas G is discharged in a second direction perpendicular to the first direction. Specifically, the gas G is discharged toward the space between the side wall portion 324 and the first power storage stack 21. When the pressure in the storage space reaches a predetermined value and the case-side exhaust valve 42 is opened, the gas G moves in the first direction toward the side opposite to the side where the first connector 81 and the second connector 82 are located, as indicated by arrow AR1, and is discharged to the outside from the case-side exhaust valve 42, as indicated by arrow AR2.

[0051] When gas is discharged from any of the unit cells 210 of the second power storage stack 22, the gas flows in the same manner as when gas is discharged from the first power storage stack 21.

[0052] In this way, in the energy storage device 10 according to the present embodiment, it is possible to prevent gas discharged from the first energy storage stack 21 or the second energy storage stack 22 from heading toward the first connector 81 and the second connector 82. This prevents debris such as metallic foreign matter contained in the gas from electrically connecting the first connector 81 and the second connector 82, causing a short circuit between the total positive terminal 15 and the total negative terminal 16 via the wiring 83, 84.

[0053] Similarly, the portion of wiring 83 routed near the first connector 81 (specifically, the portion of wiring 83 located between the first wall portion 322 and the first storage stack 21) and the portion of wiring 84 routed near the second connector 82 (specifically, the portion of wiring 84 located between the first wall portion 322 and the first storage stack 21) are electrically connected by debris, which prevents a short circuit between the total positive terminal 15 and the total negative terminal 16 via the wiring 83, 84.

[0054] (Embodiment 2) FIG. 5 is a diagram illustrating the flow of gas discharged from the power storage stack in the power storage device according to the second embodiment.

[0055] 5, when compared with the power storage device 10 according to the first embodiment, the power storage device 10A according to the second embodiment differs in the structure of the accommodating case 30 and the path through which the gas flows. The other configurations are substantially the same.

[0056] The accommodation case 30 includes a side wall portion 324 serving as a third wall portion and a side wall portion 325 serving as a fourth wall portion, and a plurality of inlets 324h are provided in the accommodation case 30. Specifically, the plurality of inlets 324h are provided in the side wall portion 324. Each of the plurality of inlets 324h is provided to face in the second direction relative to an exhaust valve 215 provided in each of the first power storage stack 21 and the second power storage stack 22.

[0057] Further, the side wall portion 324 and the second wall portion 323 are provided with exhaust flow paths that connect the multiple inlets 324h to the case-side exhaust valve 42. The cross member 70 may be provided in a state in which the side wall portion 324 and the side wall portion 325 are connected to each other, or may be provided in a state in which a gap is formed between the pair of side wall portions 324, 325.

[0058] In embodiment 2, for example, when gas G is discharged from one of the unit cells 210 of the first storage stack 21, the gas G is introduced into the exhaust flow path from an inlet 324h that faces the exhaust valve 215 in the second direction, and is discharged to the outside through the case-side exhaust valve 42 through the exhaust flow path, as shown by arrow AR3 in the figure.

[0059] Even when configured as described above, the power storage device 10A according to embodiment 2 can achieve substantially the same effects as the power storage device 10 according to embodiment 1. In addition, since an exhaust flow path is provided in the outer wall portion of the housing case 30 (more specifically, the side wall portion 324 and the second wall portion 323), accumulation of debris contained in the gas within the storage space of the housing case 30 can be suppressed, and a short circuit in the first power storage stack 21 or the second power storage stack 22 due to the debris can be suppressed.

[0060] (Embodiment 3) 6 is a cross-sectional view of a power storage device according to embodiment 3. With reference to FIG. 6, a power storage device 10B according to embodiment 3 will be described.

[0061] 6, when compared with the power storage device 10A according to the first embodiment, the power storage device 10B according to the third embodiment differs mainly in the number of power storage stacks included in the power storage module 20 and the structure of the accommodating case 30. The other configurations are substantially the same.

[0062] In the third embodiment, the power storage module 20 includes a first power storage stack 21, a second power storage stack 22, and a third power storage stack 23. The first power storage stack 21, the second power storage stack 22, and the third power storage stack 23 are arranged side by side in the first direction.

[0063] The areas in which the first power storage stack 21, the second power storage stack 22, and the third power storage stack 23 are arranged are partitioned by cross members 71 and 72. The cross member 71 is arranged between the first power storage stack 21 and the second power storage stack 22. The cross member 72 is arranged between the second power storage stack 22 and the third power storage stack 23.

[0064] The first power storage stack 21, the second power storage stack 22, and the third power storage stack 23 are connected in series by electrical connection members 51 and 52. The electrical connection member 51 electrically connects the first power storage stack 21 and the second power storage stack 22. The electrical connection member 51 is provided across a cross member 71. The electrical connection member 52 electrically connects the second power storage stack 22 and the third power storage stack 23. The electrical connection member 52 is provided across the cross member 72.

[0065] In the third embodiment as well, the first connector 81 and the second connector 82 (not shown in FIG. 6) are provided on the first wall portion 322, and the case-side exhaust valve 42 is provided on the second wall portion 323. The first power storage stack 21, the second power storage stack 22, and the third power storage stack 23 are provided such that the respective exhaust valves 215 face the second direction and are capable of discharging gas in the second direction. Therefore, the power storage device 10B according to the third embodiment can also achieve substantially the same effects as the power storage device 10 according to the first embodiment.

[0066] (Other variations) In the above-described first and second embodiments, the case where two power storage stacks are arranged is illustrated as an example, but the present invention is not limited thereto, and as long as the power storage stack is configured to be able to discharge gas in the second direction, one power storage stack may be arranged, or multiple power storage stacks may be arranged in a matrix. Also, in the above-described third embodiment, the case where the number of power storage stacks is three is illustrated as an example, but the present invention is not limited thereto, and the number may be four or more.

[0067] In the above-described first to third embodiments, the case where the exhaust valve 215 provided in each unit cell 210 of the first power storage stack 21 and the second power storage stack 22 faces one side in the second direction has been described as an example, but the present invention is not limited to this. The unit cells 210 may be arranged in the first direction with the exhaust valves 215 provided in the first power storage stack 21 and the second power storage stack 22 alternately positioned on one side and the other side in the second direction.

[0068] Furthermore, in the above-described second embodiment, the exhaust valves 215 included in the first power storage stack 21 may be located on one side in the second direction, and the exhaust valves 215 included in the second power storage stack 22 may be located on the other side in the second direction. In this case, a plurality of inlets 324h corresponding to the exhaust valves 215 of the first power storage stack 21 may be provided in the side wall portion 324, and a plurality of inlets corresponding to the exhaust valves of the second power storage stack 22 may be provided in the side wall portion 325. Alternatively, the exhaust valves 215 included in the first power storage stack 21 and the second power storage stack 22 may be located on the other side in the second direction, and the side wall portion 325 serving as the fourth wall portion may be provided with a plurality of inlets and an exhaust flow path connecting the plurality of inlets and the case exhaust valve 42.

[0069] In the above-described first to third embodiments, the first direction is parallel to the longitudinal direction of the vehicle and the second direction is parallel to the width direction of the vehicle, but the present invention is not limited to this. The first direction may be parallel to the width direction of the vehicle and the second direction may be parallel to the longitudinal direction of the vehicle.

[0070] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0071] REFERENCE SIGNS LIST 1 vehicle, 2 vehicle body, 3 front wheel, 4 rear wheel, 5 frame member, 6 side member, 7 side sill, 8 fastening member, 9 cross frame member, 10, 10A, 10B energy storage device, 10a upper surface, 15 total positive terminal, 16 total negative terminal, 20 energy storage module, 21 first energy storage stack, 22 second energy storage stack, 23 third energy storage stack, 25 electrode body, 30 housing case, 31 upper member, 32 lower member, 35 main body portion, 36 fixed portion, 42 case side exhaust valve, 50, 51, 52 electrical connection member, 70, 71, 72 cross member, 81 first connector, 82 second connector, 83, 84 wiring, 210 unit cell, 211, 221 housing, 215 exhaust valve, 217 positive external terminal, 218 Negative electrode external terminal, 321 bottom wall portion, 322 first wall portion, 323 second wall portion, 324, 325 side wall portions, 324h inlet, G gas.

Claims

1. a storage module including one or more storage stacks and having a total positive terminal and a total negative terminal; a housing case that houses the power storage module; a case-side exhaust valve provided in the housing case; a first connector electrically connected to the general positive terminal and a second connector electrically connected to the general negative terminal, the storage case has a first wall portion and a second wall portion facing each other in a first direction, the first connector and the second connector are provided on the first wall portion, the case-side exhaust valve is provided in the second wall portion, The energy storage device, wherein each of the one or more energy storage stacks is configured to be able to discharge gas in a second direction perpendicular to the first direction.

2. The power storage device according to claim 1 , wherein the gas discharged from any one of the one or more power storage stacks passes through a space within the accommodating case and is discharged from the case-side exhaust valve.

3. the housing case includes a third wall portion and a fourth wall portion connecting both end portions of the first wall portion and the second wall portion in the second direction, respectively; 2 . The power storage device according to claim 1 , wherein at least one of the third wall portion and the fourth wall portion is provided with an inlet through which the gas is introduced, and a flow path connecting the inlet and the case-side exhaust valve.

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