Electric storage device

Abstract

To improve the exhaust efficiency in an electric storage device that houses an electric storage cell with a cell exhaust valve provided on a side surface of the electric storage cell.SOLUTION: An electric storage device 1 includes a plurality of electric storage cells 10 and a housing case 20. Each of the electric storage cells 10 includes a cell exhaust valve that is provided on a side surface of the electric storage cell 10 and exhausts gas in the electric storage cell 10. The housing case 20 includes a lower case 22, an upper case 21, and a case exhaust valve 23. The case exhaust valve 23 is provided above or below the center of the housing case 20 in the height direction. When the case exhaust valve 23 is provided above the center of the housing case 20, the cell exhaust valve is provided above the center of the electric storage cell 10 in the height direction. When the case exhaust valve 23 is provided below the center of the housing case 20, the cell exhaust valve is provided below the center of the electric storage cell 10 in the height direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Japanese Patent Publication No. 2023-17448 (Patent Document 1) discloses a battery pack in which a terminal and a smoke exhaust valve for exhausting gas from the battery cell are provided on the top of the battery cell, and the gas exhausted from the smoke exhaust valve is exhausted from an exhaust duct provided on the top of the battery pack. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-17448 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there are cases where battery cells with smoke exhaust valves provided on the side surfaces of the battery cells are housed in a battery pack. In such cases, if an exhaust duct is provided on the top of the battery pack, the distance between the smoke exhaust valve and the exhaust duct increases, which may reduce smoke exhaust efficiency. There is a demand for improved smoke exhaust efficiency in power storage devices that house power storage cells with smoke exhaust valves provided on the side surfaces of the power storage cells.

[0005] An object of the present disclosure is to improve the smoke exhaust efficiency in an electricity storage device that houses electricity storage cells in which cell smoke exhaust valves are provided on the side surfaces of the electricity storage cells. [Means for solving the problem]

[0006] An energy storage device according to an aspect of the present disclosure includes a plurality of energy storage cells and a housing case that houses the plurality of energy storage cells. Each of the plurality of energy storage cells includes a cell smoke vent valve that is provided on a side surface of the energy storage cell and that vents gas inside the energy storage cell. The housing case includes a lower case, an upper case, and a case smoke vent valve that vents gas inside the housing case. The case smoke vent valve is provided above or below the center of the housing case in the vertical direction. When the case smoke vent valve is provided above the center of the housing case, the cell smoke vent valve is provided above the center of the energy storage cells in the vertical direction. When the case smoke vent valve is provided below the center of the housing case, the cell smoke vent valve is provided below the center of the energy storage cells in the vertical direction.

[0007] Preferably, the case smoke vent valve is provided above the center of the lower case or on the upper case, and the cell smoke vent valve is provided above the center of the electricity storage cell in the up-down direction.

[0008] Preferably, the case smoke vent valve is provided below the center of the lower case, and the cell smoke vent valve is provided below the center of the electricity storage cell in the up-down direction.

[0009] Preferably, the power storage device is mounted on a vehicle. Each of the plurality of power storage cells includes an upper surface, a lower surface, a pair of short side surfaces, and a pair of long side surfaces. The pair of long side surfaces are arranged at a distance from each other in the width direction of the vehicle. Each of the pair of long side surfaces is formed to extend in the front-rear direction of the vehicle. The pair of short side surfaces are provided at a distance from each other in the front-rear direction of the vehicle. The cell smoke exhaust valve is provided on one of the pair of short side surfaces.

[0010] Preferably, the power storage device is mounted on a vehicle. Each of the plurality of power storage cells includes an upper surface, a lower surface, a pair of short side surfaces, and a pair of long side surfaces. The pair of long side surfaces are arranged at a distance from each other in the front-to-rear direction of the vehicle. Each of the pair of long side surfaces is formed to extend in the width direction of the vehicle. The pair of short side surfaces are arranged at a distance from each other in the width direction of the vehicle. The cell smoke exhaust valve is provided on one of the pair of short side surfaces.

[0011] Preferably, the lower surface and the lower case are fixed together with an adhesive. [Effects of the Invention]

[0012] According to the present disclosure, smoke exhaust efficiency is improved in an electricity storage device that houses electricity storage cells in which cell smoke exhaust valves are provided on the side surfaces of the electricity storage cells. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view schematically showing an electricity storage device according to a first embodiment. [Figure 2] FIG. 1 is a diagram schematically illustrating an example of a storage cell 10. [Figure 3] 2 is a diagram schematically showing a cross section of the energy storage device 1 when the energy storage device 1 is cut along a plane passing through a case smoke exhaust valve 23 and parallel to a short side surface 13 of an energy storage cell 10. FIG. [Figure 4] FIG. 10 is a perspective view schematically showing an electricity storage device according to a second embodiment. [Figure 5] FIG. 10 is a perspective view schematically showing an electricity storage device according to a third embodiment. [Figure 6] FIG. 2 is a diagram schematically illustrating an example of a storage cell 10B. [Figure 7] FIG. 10 is a perspective view schematically showing an electricity storage device according to a fourth embodiment. [Figure 8] FIG. 10 is a cross-sectional view schematically showing an electricity storage device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments and modifications according to the present disclosure will be described with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. Note that the embodiments and modifications described below may be selectively combined as appropriate.

[0015] [Embodiment 1] The electricity storage device according to the first embodiment will be described with reference to Figures 1 to 3. Figure 1 is a perspective view schematically showing the electricity storage device according to the first embodiment.

[0016] 1, a power storage device 1 according to the first embodiment is mounted on a vehicle for use, for example. Examples of the vehicle include a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, and an electric vehicle. The power storage device 1 includes a plurality of power storage cells 10 and a housing case 20 that houses the plurality of power storage cells 10.

[0017] The energy storage cell 10 is a secondary battery, typically a lithium-ion secondary battery. A lithium-ion secondary battery is a battery that uses lithium as a charge carrier, and may include not only a typical lithium-ion secondary battery that uses a liquid electrolyte, but also a so-called all-solid-state battery that uses a solid electrolyte. Note that the energy storage cell 10 is not limited to a lithium-ion secondary battery, and may be composed of a nickel-metal hydride secondary battery or other secondary battery.

[0018] The energy storage cells 10 are arranged to extend in the front-rear direction D1 of the vehicle. The energy storage cells 10 are also arranged along the width direction D2 of the vehicle.

[0019] The storage case 20 includes an upper case 21, a lower case 22, and a case smoke exhaust valve 23. The lower case 22 includes a bottom plate, a peripheral wall, and a plurality of partition walls 60, 61, 62, 63, and 64. The plurality of partition walls 60, 61, 62, 63, and 64 divide the space within the storage case 20 into a plurality of sections.

[0020] The bottom plate is formed in a flat plate shape. The peripheral wall is formed to extend upward from the outer peripheral edge of the bottom plate and is formed in an annular shape. Partition walls 60, 61, 62, 63, and 64 are provided on the bottom plate. Partition walls 60, 61, 62, and 63 are formed to extend in the front-to-rear direction D1 of the vehicle, and partition wall 64 is formed to extend in the width direction D2 of the vehicle. Partition wall 64 is disposed at the center of the front-to-rear direction D1 of the vehicle. Partition wall 60 and partition wall 63 are disposed at the center of the width direction D2 of the vehicle. Partition wall 60 is disposed forward of partition wall 64, and partition wall 63 is disposed rearward of partition wall 64. The multiple energy storage cells 10 are accommodated in a space formed by assembling upper case 21 to lower case 22. FIG. 1 shows energy storage device 1 with upper case 21 removed.

[0021] The case smoke exhaust valve 23 is configured to exhaust gas inside the storage case 20. The case smoke exhaust valve 23 is provided in the upper case 21.

[0022] FIG. 2 is a diagram schematically illustrating an example of a storage cell 10. Referring to FIG. 2, the storage cell 10 includes an upper surface 11, a lower surface 12, a pair of short side surfaces 13 and 14, and a pair of long side surfaces 15 and 16. The pair of short side surfaces 13 and 14 are spaced apart in the front-to-rear direction D1 of the vehicle. The pair of long side surfaces 15 and 16 are spaced apart in the width direction D2 of the vehicle. Each of the pair of long side surfaces 15 and 16 is formed to extend in the front-to-rear direction D1 of the vehicle. The short side surfaces 13 and 14 and the long side surfaces 15 and 16 are referred to as "side surfaces" in the present disclosure.

[0023] The energy storage cell 10 further includes a positive electrode terminal 17 and a negative electrode terminal 18. The positive electrode terminal 17 is provided on one of the pair of short side surfaces 13, 14, and the negative electrode terminal 18 is provided on the other of the pair of short side surfaces 13, 14. In the example shown in FIG. 2 , the positive electrode terminal 17 is provided on the short side surface 14, and the negative electrode terminal 18 is provided on the short side surface 13. Note that both the positive electrode terminal 17 and the negative electrode terminal 18 may be provided on one of the pair of short side surfaces 13, 14.

[0024] The energy storage cell 10 further includes a cell smoke vent valve 19 that exhausts gas within the energy storage cell 10. The cell smoke vent valve 19 is configured to exhaust gas inside the energy storage cell 10 to the outside of the energy storage cell 10 when the internal pressure of the energy storage cell 10 increases. The gas exhausted from the cell smoke vent valve 19 is at a high temperature. The cell smoke vent valve 19 is provided on a side surface of the energy storage cell 10. More specifically, the cell smoke vent valve 19 is provided on one of a pair of short side surfaces 13, 14. In the example shown in FIG. 2, the cell smoke vent valve 19 is provided on the short side surface 13 on which the negative electrode terminal 18 is provided. A two-dot chain line 71 indicates the center position of the energy storage cell 10 in the up-down direction D3 of the energy storage device 1 (see FIG. 1). The cell smoke vent valve 19 is provided above the center of the energy storage cell 10 in the up-down direction D3 of the energy storage device 1.

[0025] 3 is a diagram schematically illustrating a cross section of the energy storage device 1 when the energy storage device 1 is cut along a plane passing through the case smoke exhaust valve 23 and parallel to the short side surface 13 of the energy storage cell 10. Note that in FIG. 3, hatching indicating the cross section of the energy storage cell 10 has been omitted in consideration of ease of viewing the drawing.

[0026] 3, a two-dot chain line 72 indicates the center position of the storage case 20 in the vertical direction D3 of the energy storage device 1. As shown in FIG. 3, the case smoke exhaust valve 23 is provided above the center of the storage case 20 in the vertical direction D3 of the energy storage device 1.

[0027] The lower surfaces 12 of the energy storage cells 10 and the lower case 22 are fixed together with an adhesive 30. The energy storage device 1 further includes a cooler 40 that cools the energy storage cells 10. The cooler 40 is provided on the energy storage cells 10. More specifically, the cooler 40 is provided in the space between the upper surfaces 11 of the energy storage cells 10 and the upper case 21, along the upper surfaces 11. As a result, the cooler 40 is located near the cell smoke vent 19 (see FIG. 2 ).

[0028] A space 50 in which the cooler 40 is not provided is provided in the space between the top surface 11 of the energy storage cell 10 and the upper case 21. The space 50 includes at least a part of the area facing the case smoke exhaust valve 23. The space 50 is formed above the partition wall 60.

[0029] Therefore, in the energy storage device 1, the cell smoke vent valve 19 (see FIG. 2), the cooler 40, the space 50, and the case smoke vent valve 23 are provided above the center of the storage case 20 in the up-down direction D3 of the energy storage device 1. Gas discharged from the cell smoke vent valve 19 (see FIG. 2) moves within the storage case 20 along the short side surface 13 (see FIG. 2) and reaches the vicinity of the cooler 40. When the storage case 20 is filled with gas, the internal pressure within the storage case 20 increases. This causes the upper case 21 to deform and bulge upward. Meanwhile, because the lower case 22 and each energy storage cell 10 are fixed by the adhesive 30, deformation of the lower case 22 is suppressed. When the upper case 21 deforms and bulges upward, a gap is formed between the upper case 21 and the cooler 40, and gas accumulates in this gap.

[0030] Thereafter, when the internal pressure of the storage case 20 reaches or exceeds a predetermined pressure, the case smoke vent valve 23 opens, and the gas inside the storage case 20 is discharged to the outside. At this time, because the case smoke vent valve 23 is provided in the upper case 21 and the gas is also accumulated between the upper case 21 and the cooler 40, the gas is efficiently discharged to the outside through the case smoke vent valve 23. Specifically, the gas discharged from the cell smoke vent valve 19 moves through the gap to the space 50, passes through the space 50, and is discharged from the case smoke vent valve 23 to the outside of the storage case 20. Therefore, according to the energy storage device 1, the smoke exhaust efficiency of discharging the gas discharged from the cell smoke vent valve 19 to the outside of the storage case 20 through the case smoke vent valve 23 is improved.

[0031] Here, the gas discharged from the cell smoke exhaust valve 19 is at a high temperature, and as described above, the gas accumulates in the upper part of the storage case 20. On the other hand, a cooler 40 is disposed on the upper surface 11 of each energy storage cell 10, which can prevent the upper surface 11 of each energy storage cell 10 and the like from being deteriorated by the heat from the high-temperature gas. In addition, a partition wall 60 is disposed below the space 50, which prevents the energy storage cells 10 from being exposed to the high-temperature gas when the gas flows through the space 50.

[0032] Furthermore, in the energy storage device 1, the cooler 40 is provided near the cell smoke vent valve 19. Therefore, according to the energy storage device 1, the gas discharged from the cell smoke vent valve 19 is cooled relatively quickly. Furthermore, in the energy storage device 1, the cooler 40 is provided in the path of the gas discharged from the cell smoke vent valve 19. Therefore, the gas discharged from the cell smoke vent valve 19 is gradually cooled on its way to the case smoke vent valve 23. Therefore, according to the energy storage device 1, damage to the energy storage cells 10 and the upper case 21 by the high-temperature gas discharged from the cell smoke vent valve 19 is suppressed.

[0033] As described above, in the energy storage device 1 according to the first embodiment, the case smoke vent valve 23 is provided above the center of the storage case 20 in the vertical direction D3 of the energy storage device 1, and the cell smoke vent valve 19 is provided above the center of the energy storage cells 10 in the vertical direction D3 of the energy storage device 1. With this configuration, the smoke vent path that gas discharged from the cell smoke vent valve 19 takes from the case smoke vent valve 23 to the outside of the storage case 20 can be made shorter than when the cell smoke vent valve 19 is provided below the center of the energy storage cells 10 in the vertical direction D3 of the energy storage device 1. Therefore, with the energy storage device 1 according to the first embodiment, when the cell smoke vent valve 19 is provided on the side surface of the energy storage cells 10, the smoke vent efficiency of discharging gas discharged from the cell smoke vent valve 19 from the case smoke vent valve 23 to the outside of the storage case 20 is improved. Furthermore, according to the electricity storage device 1 of the first embodiment, the smoke exhaust path can be shortened, so that the area over which the high-temperature gas exhausted from the cell smoke exhaust valve 19 comes into contact with the electricity storage cells 10 can be reduced.

[0034] Furthermore, in the energy storage device 1 according to the first embodiment, the cell smoke vent valve 19 is provided on one of the pair of short side surfaces 13, 14 of the energy storage cell 10 (for example, the short side surface 13). With this configuration, the gas discharged from the cell smoke vent valve 19 rises inside the storage case 20 along the short side surface 13. If the cell smoke vent valve 19 were provided on one of the pair of long side surfaces 15, 16 of the energy storage cell 10, the gas discharged from the cell smoke vent valve 19 would rise inside the storage case 20 along the long side surface 15 or 16. Therefore, if the cell smoke vent valve 19 is provided on one of the pair of long side surfaces 15, 16 of the energy storage cell 10, the area over which the high-temperature gas discharged from the cell smoke vent valve 19 comes into contact with the energy storage cell 10 becomes larger. However, in the energy storage device 1 according to the first embodiment, the cell smoke vent valve 19 is provided on one of the pair of short side surfaces 13, 14 of the energy storage cell 10. Therefore, according to the energy storage device 1 according to the first embodiment, the area over which the high-temperature gas discharged from the cell smoke vent valve 19 comes into contact with the energy storage cell 10 can be reduced compared to when the cell smoke vent valve 19 is provided on one of the pair of long side surfaces 15, 16 of the energy storage cell 10.

[0035] Furthermore, in the energy storage device 1 according to the first embodiment, the lower surfaces 12 of the energy storage cells 10 and the lower case 22 are fixed together with the adhesive 30. With the above-described configuration, the energy storage device 1 according to the first embodiment allows the gas discharged from the cell smoke vent valve 19 to rise within the accommodating case 20 along the short side surface 13, pass through the space 50, and be discharged to the outside of the accommodating case 20 from the case smoke vent valve 23. Therefore, according to the energy storage device 1 according to the first embodiment, it is possible to prevent the high-temperature gas discharged from the cell smoke vent valve 19 from coming into contact with the adhesive 30.

[0036] [Embodiment 2] The electricity storage device according to the second embodiment will be described with reference to Fig. 4. Fig. 4 is a perspective view schematically showing the electricity storage device according to the second embodiment.

[0037] 4, power storage device 1A according to embodiment 2 differs from power storage device 1 according to embodiment 1 (see FIG. 1) in the position of case smoke vent valve 23. In power storage device 1A according to embodiment 2, case smoke vent valve 23 is provided in lower case 22. In other respects, power storage device 1A according to embodiment 2 is the same as power storage device 1 according to embodiment 1 (see FIG. 1), and therefore description thereof will not be repeated.

[0038] 4 shows the energy storage device 1A with the upper case 21 removed. A two-dot chain line 73 indicates the center position of the accommodating case 20 in the vertical direction D3 of the energy storage device 1A. In the energy storage device 1A, the case smoke vent valve 23 is provided above the center of the accommodating case 20 in the vertical direction D3 of the energy storage device 1A. That is, in the energy storage device 1A, the case smoke vent valve 23 is provided above the center of the lower case 22 in the vertical direction D3 of the energy storage device 1A. Gas discharged from the cell smoke vent valve 19 (see FIG. 2) moves along the short side surface 13 (see FIG. 2) and is discharged to the outside of the accommodating case 20 through the case smoke vent valve 23 (see FIG. 4).

[0039] As described above, in the energy storage device 1A according to the second embodiment, the case smoke vent valve 23 is provided above the center of the storage case 20 in the vertical direction D3 of the energy storage device 1A, and the cell smoke vent valve 19 is provided above the center of the energy storage cells 10 in the vertical direction D3 of the energy storage device 1A. With this configuration, the smoke vent path that gas discharged from the cell smoke vent valve 19 takes from the case smoke vent valve 23 to the outside of the storage case 20 can be made shorter than when the cell smoke vent valve 19 is provided below the center of the energy storage cells 10 in the vertical direction D3 of the energy storage device 1A. Therefore, according to the energy storage device 1A according to the second embodiment, when the cell smoke vent valve 19 is provided on the side surface of the energy storage cells 10, the smoke vent efficiency of discharging gas discharged from the cell smoke vent valve 19 from the case smoke vent valve 23 to the outside of the storage case 20 is improved. Furthermore, according to the electricity storage device 1A of the second embodiment, the smoke exhaust path can be shortened, so that the area where the high-temperature gas exhausted from the cell smoke exhaust valve 19 comes into contact with the electricity storage cells 10 can be reduced.

[0040] Furthermore, in the energy storage device 1A according to the second embodiment, the cell smoke vent valve 19 is provided on one of the pair of short side surfaces 13, 14 of the energy storage cell 10 (for example, the short side surface 13). With this configuration, gas discharged from the cell smoke vent valve 19 moves along the short side surface 13 and is discharged to the outside of the storage case 20 through the case smoke vent valve 23. If the cell smoke vent valve 19 were provided on one of the pair of long side surfaces 15, 16 of the energy storage cell 10, the gas discharged from the cell smoke vent valve 19 would move inside the storage case 20 along the long side surface 15 or 16. Therefore, if the cell smoke vent valve 19 is provided on one of the pair of long side surfaces 15, 16 of the energy storage cell 10, the area over which the high-temperature gas discharged from the cell smoke vent valve 19 comes into contact with the energy storage cell 10 would be increased. However, in the energy storage device 1A according to the second embodiment, the cell smoke vent valve 19 is provided on one of the pair of short side surfaces 13, 14 of the energy storage cell 10. Therefore, according to the energy storage device 1A according to the second embodiment, the area over which the high-temperature gas discharged from the cell smoke vent valve 19 comes into contact with the energy storage cell 10 can be reduced compared to when the cell smoke vent valve 19 is provided on one of the pair of long side surfaces 15, 16 of the energy storage cell 10.

[0041] Furthermore, in the energy storage device 1A according to the second embodiment, the lower surfaces 12 of the energy storage cells 10 and the lower case 22 are fixed together with the adhesive 30. With the above-described configuration, the energy storage device 1A according to the second embodiment allows the gas discharged from the cell smoke vent valve 19 to move along the short side surface 13 and be discharged to the outside of the storage case 20 through the case smoke vent valve 23. Therefore, according to the energy storage device 1A according to the second embodiment, it is possible to prevent the high-temperature gas discharged from the cell smoke vent valve 19 from coming into contact with the adhesive 30.

[0042] [Embodiment 3] The electricity storage device according to the third embodiment will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a perspective view schematically showing the electricity storage device according to the third embodiment.

[0043] Referring to FIG. 5, power storage device 1B according to embodiment 3 differs from power storage device 1 according to embodiment 1 (see FIG. 1) in two respects. The first point is that power storage device 1B according to embodiment 3 includes a plurality of power storage cells 10B instead of a plurality of power storage cells 10 (see FIG. 1). The second point is the position of case smoke vent valve 23. In power storage device 1B according to embodiment 3, case smoke vent valve 23 is provided in lower case 22. In other respects, power storage device 1B according to embodiment 3 is the same as power storage device 1 according to embodiment 1 (see FIG. 1), and therefore description thereof will not be repeated.

[0044] 5 shows the energy storage device 1B with the upper case 21 removed. A plurality of energy storage cells 10B are housed in a housing case 20. The energy storage cells 10B are arranged to extend in the front-to-rear direction D1 of the vehicle. The energy storage cells 10B are also arranged along the width direction D2 of the vehicle.

[0045] A two-dot chain line 74 indicates the center position of lower case 22 in the up-down direction D3 of power storage device 1B. In power storage device 1B, case smoke exhaust valve 23 is provided below the center of lower case 22 in the up-down direction D3 of power storage device 1B. That is, in power storage device 1B, case smoke exhaust valve 23 is provided below the center of containing case 20 in the up-down direction D3 of power storage device 1B.

[0046] Fig. 6 is a diagram schematically showing an example of a storage cell 10B. The storage cell 10B differs from the above-described storage cell 10 (see Fig. 2) in the positions of the cell smoke vent valve 19 and the negative electrode terminal 18. In other respects, the storage cell 10B is the same as the above-described storage cell 10 (see Fig. 2), and therefore description thereof will not be repeated.

[0047] The cell smoke vent valve 19 is provided on a side surface of the energy storage cell 10B. More specifically, the cell smoke vent valve 19 is provided on one of the pair of short side surfaces 13, 14. In the example shown in FIG. 6, the cell smoke vent valve 19 is provided on the short side surface 13 on which the negative electrode terminal 18 is provided. A two-dot chain line 75 indicates the position of the center of the energy storage cell 10B in the vertical direction D3 of the energy storage device 1B (see FIG. 5). The cell smoke vent valve 19 is provided below the center of the energy storage cell 10B in the vertical direction D3 of the energy storage device 1B. The negative electrode terminal 18 is provided at a position within the short side surface 13 so as not to overlap with the cell smoke vent valve 19.

[0048] It should be noted that both the positive electrode terminal 17 and the negative electrode terminal 18 may be provided on one of the pair of short side surfaces 13, 14.

[0049] As described above, in the energy storage device 1B according to the third embodiment, the case smoke vent valve 23 is provided below the center of the storage case 20 in the vertical direction D3 of the energy storage device 1B, and the cell smoke vent valve 19 is provided below the center of the energy storage cells 10B in the vertical direction D3 of the energy storage device 1B. With this configuration, the smoke vent path that the gas discharged from the cell smoke vent valve 19 takes from the case smoke vent valve 23 to the outside of the storage case 20 can be made shorter than when the cell smoke vent valve 19 is provided above the center of the energy storage cells 10B in the vertical direction D3 of the energy storage device 1B. Therefore, with the energy storage device 1B according to the third embodiment, when the cell smoke vent valve 19 is provided on the side surface of the energy storage cells 10B, the smoke vent efficiency of discharging the gas discharged from the cell smoke vent valve 19 from the case smoke vent valve 23 to the outside of the storage case 20 is improved. Furthermore, according to the electricity storage device 1B of the third embodiment, the smoke exhaust path can be shortened, and therefore the area over which the high-temperature gas exhausted from the cell smoke exhaust valve 19 comes into contact with the electricity storage cells 10B can be reduced.

[0050] Furthermore, in the energy storage device 1B according to the third embodiment, the cell smoke vent valve 19 is provided on one of the pair of short side surfaces 13, 14 of the energy storage cell 10B (for example, the short side surface 13). With this configuration, gas discharged from the cell smoke vent valve 19 moves along the short side surface 13 and is discharged to the outside of the storage case 20 through the case smoke vent valve 23. If the cell smoke vent valve 19 were provided on one of the pair of long side surfaces 15, 16 of the energy storage cell 10B, the gas discharged from the cell smoke vent valve 19 would move within the storage case 20 along the long side surface 15 or 16. Therefore, if the cell smoke vent valve 19 is provided on one of the pair of long side surfaces 15, 16 of the energy storage cell 10B, the area over which the high-temperature gas discharged from the cell smoke vent valve 19 comes into contact with the energy storage cell 10B would be increased. However, in the energy storage device 1B according to the third embodiment, the cell smoke vent valve 19 is provided on one of the pair of short side surfaces 13, 14 of the energy storage cell 10B. Therefore, according to the energy storage device 1B according to the third embodiment, the area over which the high-temperature gas discharged from the cell smoke vent valve 19 comes into contact with the energy storage cell 10B can be reduced compared to when the cell smoke vent valve 19 is provided on one of the pair of long side surfaces 15, 16 of the energy storage cell 10B.

[0051] Furthermore, in the energy storage device 1B according to the third embodiment, the bottom surfaces 12 of the energy storage cells 10B and the lower case 22 are fixed together with the adhesive 30. With the above-described configuration, the energy storage device 1B according to the third embodiment allows the gas discharged from the cell smoke vent valve 19 to move along the short side surface 13 and be discharged to the outside of the storage case 20 through the case smoke vent valve 23. Therefore, according to the energy storage device 1B according to the third embodiment, it is possible to prevent the high-temperature gas discharged from the cell smoke vent valve 19 from coming into contact with the adhesive 30.

[0052] [Embodiment 4] An electricity storage device according to embodiment 4 will be described with reference to Fig. 7, Fig. 8, and Fig. 2. Fig. 7 is a perspective view schematically showing the electricity storage device according to embodiment 4. Fig. 8 is a cross-sectional view schematically showing the electricity storage device according to embodiment 4.

[0053] 7, power storage device 1C according to embodiment 4 differs from power storage device 1 according to embodiment 1 (see FIG. 1) in the arrangement of power storage cells 10. In power storage device 1C according to embodiment 4, power storage cells 10 are arranged to extend in width direction D2 of the vehicle, and a plurality of power storage cells 10 are arranged along front-rear direction D1 of the vehicle. In other respects, power storage device 1C according to embodiment 4 is the same as power storage device 1 according to embodiment 1 (see FIG. 1).

[0054] 8, a cross section of the energy storage device 1C is shown schematically when the energy storage device 1C is cut along a plane that passes through the case smoke vent valve 23 and is parallel to the long side surface 16 of the energy storage cell 10. In addition, in FIG. 8, hatching indicating the cross sections of the energy storage cell 10, the cell smoke vent valve 19, the positive electrode terminal 17, and the negative electrode terminal 18 is omitted in consideration of ease of viewing the drawing.

[0055] 2 and 8, in an energy storage device 1C according to the fourth embodiment, a pair of short side surfaces 13, 14 of an energy storage cell 10 are spaced apart in a width direction D2 of the vehicle, and a pair of long side surfaces 15, 16 are spaced apart in a front-to-rear direction D1 of the vehicle. In addition, in the energy storage device 1C according to the fourth embodiment, each of the pair of long side surfaces 15, 16 is formed to extend in the width direction D2 of the vehicle. In the energy storage device 1C according to the fourth embodiment, the cell smoke vent valve 19 is also provided on one of the pair of short side surfaces 13, 14. In the example shown in FIGS. 2 and 8, the cell smoke vent valve 19 is provided on the short side surface 13.

[0056] 8, a two-dot chain line 76 indicates the center position of the accommodating case 20 in the vertical direction D3 of the energy storage device 1C. The case smoke vent valve 23 is provided above the center of the accommodating case 20 in the vertical direction D3 of the energy storage device 1C. In other words, the case smoke vent valve 23 is provided above the center of the lower case 22 in the vertical direction D3 of the energy storage device 1C. Furthermore, the cell smoke vent valve 19 is provided above the center of the energy storage cells 10 in the vertical direction D3 of the energy storage device 1C.

[0057] Similarly to the energy storage device 1 (see FIG. 1 ), the energy storage device 1C also includes a cooler 40 that cools the energy storage cells 10. The cooler 40 is provided on the energy storage cells 10. More specifically, the cooler 40 is provided in the space between the upper surface 11 of the energy storage cells 10 and the upper case 21, along the upper surface 11. As a result, the cooler 40 is located near the cell smoke vent valve 19.

[0058] A space 50 in which a cooler 40 is not provided is provided between the top surface 11 of the energy storage cell 10 and the upper case 21. The space 50 includes at least a part of the area facing the case smoke exhaust valve 23. The bottom surface 12 of the energy storage cell 10 and the lower case 22 are fixed together with an adhesive 30.

[0059] Thus, in the energy storage device 1C, the cell smoke vent valve 19, the cooler 40, the space 50, and the case smoke vent valve 23 are provided above the center of the containing case 20 in the up-down direction D3 of the energy storage device 1C. Therefore, in the energy storage device 1C as well, gas can be efficiently exhausted to the outside through the case smoke vent valve 23, just like in the energy storage device 1 described above.

[0060] Furthermore, in the energy storage device 1C, a cooler 40 is arranged on the upper surface 11 of each energy storage cell 10, so that the upper surface 11 of each energy storage cell 10 and the like can be prevented from being deteriorated by heat from the high-temperature gas.

[0061] Also in the energy storage device 1C, the case smoke vent valve 23 is provided above the center of the storage case 20 in the vertical direction D3 of the energy storage device 1C, and the cell smoke vent valve 19 is provided above the center of the energy storage cells 10 in the vertical direction D3 of the energy storage device 1C. This makes it possible to shorten the smoke vent path through which the gas discharged from the cell smoke vent valve 19 travels from the case smoke vent valve 23 to be discharged outside the storage case 20.

[0062] [Variation 1] 8, in the power storage device 1C, the cell smoke vent valve 19, the cooler 40, the space 50, and the case smoke vent valve 23 may be provided below the center of the storage case 20 in the up-down direction D3 of the power storage device 1C. The specific configuration of the power storage device in such a case is as follows.

[0063] The case smoke vent valve 23 is provided below the center of the storage case 20 in the vertical direction D3 of the energy storage device. That is, the case smoke vent valve 23 is provided below the center of the lower case 22 in the vertical direction D3 of the energy storage device. As an example, the case smoke vent valve 23 is provided in the lower case 22. The cell smoke vent valve 19 is provided below the center of the energy storage cell 10 in the vertical direction D3 of the energy storage device. The cooler 40 is provided along the lower surface 12 in the space between the lower surface 12 of the energy storage cell 10 and the lower case 22. As a result, the cooler 40 is located near the cell smoke vent valve 19. A space 50 in which the cooler 40 is not provided is provided in the space between the lower surface 12 of the energy storage cell 10 and the lower case 22. The space 50 includes at least a part of the area facing the case smoke vent valve 23. The upper surface 11 of the energy storage cell 10 and the upper case 21 are fixed with an adhesive 30.

[0064] In an electricity storage device configured as described above, when gas exhausted from cell smoke vent valves 19 fills the inside of storage case 20, lower case 22 deforms, forming a gap between lower case 22 and cooler 40, and gas accumulates in this gap. When the internal pressure of storage case 20 subsequently reaches a predetermined pressure or higher, case smoke vent valve 23 opens, and the gas inside storage case 20 is exhausted to the outside. At this time, because case smoke vent valve 23 is provided in lower case 22 and gas is also accumulated between lower case 22 and cooler 40, the gas is efficiently exhausted to the outside through case smoke vent valve 23. Therefore, an electricity storage device configured as described above also achieves the same effects as electricity storage device 1C.

[0065] This configuration may also be applied to the power storage device 1 (see FIG. 3). In this case, the same effects as those of the power storage device 1 are achieved.

[0066] [Variation 2] In the energy storage device 1A according to the second embodiment, the energy storage cells 10 may also be arranged so as to extend in the width direction D2 of the vehicle, and a plurality of the energy storage cells 10 may be arranged along the front-rear direction D1 of the vehicle. Referring to FIG. 2 , in this case, the pair of short side surfaces 13, 14 of the energy storage cell 10 are spaced apart in the width direction D2 of the vehicle, and the pair of long side surfaces 15, 16 are spaced apart in the front-rear direction D1 of the vehicle. Each of the pair of long side surfaces 15, 16 is formed so as to extend in the width direction D2 of the vehicle. The cell smoke vent valve 19 is provided on one of the pair of short side surfaces 13, 14. Even in this case, the same effects as those described in the second embodiment can be achieved.

[0067] Also, in the energy storage device 1B according to the third embodiment, the energy storage cell 10B may be arranged so as to extend in the width direction D2 of the vehicle, and a plurality of the energy storage cells 10B may be arranged along the front-rear direction D1 of the vehicle. Referring to FIG. 6 , in this case, the pair of short side surfaces 13, 14 of the energy storage cell 10B are spaced apart in the width direction D2 of the vehicle, and the pair of long side surfaces 15, 16 are spaced apart in the front-rear direction D1 of the vehicle. Each of the pair of long side surfaces 15, 16 is formed so as to extend in the width direction D2 of the vehicle. The cell smoke vent valve 19 is provided on one of the pair of short side surfaces 13, 14. Even in this case, the same effects as those described in the third embodiment can be achieved.

[0068] [Variation 3] 2, the cell smoke vent valve 19 may be provided on one of the pair of long side surfaces 15, 16 of the energy storage cell 10. Also, with reference to Fig. 6, the cell smoke vent valve 19 may be provided on one of the pair of long side surfaces 15, 16 of the energy storage cell 10B.

[0069] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0070] 1, 1A, 1B, 1C energy storage device, 10, 10B energy storage cell, 11 top surface, 12 bottom surface, 13, 14 short side, 15, 16 long side, 17 positive terminal, 18 negative terminal, 19 cell smoke exhaust valve, 20 storage case, 21 upper case, 22 lower case, 23 case smoke exhaust valve, 30 adhesive, 40 cooler, 50 space, 60, 61, 62, 63, 64 partition wall, 71, 72, 73, 74, 75 two-dot chain line, D1 front-to-back direction, D2 width direction, D3 up-down direction.

Claims

1. A plurality of storage cells; a storage case that stores the plurality of storage cells, each of the plurality of energy storage cells includes a cell smoke exhaust valve provided on a side surface of the energy storage cell and configured to exhaust gas within the energy storage cell; the storage case includes a lower case, an upper case, and a case smoke exhaust valve that exhausts gas inside the storage case; The case smoke exhaust valve is provided above or below the center of the storage case in the vertical direction, when the case smoke exhaust valve is provided above the center of the storage case, the cell smoke exhaust valve is provided above the center of the energy storage cell in the up-down direction, In the energy storage device, when the case smoke exhaust valve is provided below the center of the storage case, the cell smoke exhaust valve is provided below the center of the energy storage cell in the vertical direction.

2. 2. The energy storage device according to claim 1, wherein the case smoke exhaust valve is provided above the center of the lower case or in the upper case, and the cell smoke exhaust valve is provided above the center of the energy storage cell in the vertical direction.

3. The electricity storage device according to claim 1 , wherein the case smoke vent valve is provided below a center of the lower case, and the cell smoke vent valve is provided below a center of the electricity storage cell in the up-down direction.

4. The power storage device is mounted on a vehicle, Each of the plurality of storage cells includes an upper surface, a lower surface, a pair of short side surfaces, and a pair of long side surfaces; The pair of long side surfaces are arranged at an interval in the width direction of the vehicle, Each of the pair of long side surfaces is formed to extend in the front-rear direction of the vehicle, The pair of short side surfaces are spaced apart in the front-rear direction of the vehicle, The electricity storage device according to claim 1 , wherein the cell smoke exhaust valve is provided on one of the pair of short side surfaces.

5. The power storage device is mounted on a vehicle, Each of the plurality of storage cells includes an upper surface, a lower surface, a pair of short side surfaces, and a pair of long side surfaces; The pair of long side surfaces are arranged at an interval in the front-rear direction of the vehicle, Each of the pair of long side surfaces is formed to extend in the width direction of the vehicle, The pair of short side surfaces are spaced apart in the width direction of the vehicle, The electricity storage device according to claim 1 , wherein the cell smoke exhaust valve is provided on one of the pair of short side surfaces.

6. The power storage device according to claim 4 , wherein the lower surface and the lower case are fixed together with an adhesive.

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