Energy storage device

Abstract

In an energy storage device that houses energy storage cells, the cell exhaust valve is installed on the side of the energy storage cell to improve exhaust efficiency. [Solution] The energy storage device 1 comprises a plurality of energy storage cells 10 and a housing case 20. Each of the plurality of energy storage cells 10 includes a cell exhaust valve provided on the side of the energy storage cell 10 for exhausting gas from within the energy 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 located above or below the center of the housing case 20 in the vertical direction. If the case exhaust valve 23 is located above the center of the housing case 20, the cell exhaust valve is located above the center of the energy storage cell 10 in the vertical direction. If the case exhaust valve 23 is located below the center of the housing case 20, the cell exhaust valve is located below the center of the energy storage cell 10 in the vertical direction.

Description

Technical Field

[0001] The present disclosure relates to a power storage device.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2023 - 17448 (Patent Document 1) discloses a battery pack in which a terminal is provided on the upper part of a battery cell and a smoke exhaust valve for exhausting gas in the battery cell is provided, and the gas discharged from the smoke exhaust valve is discharged from an exhaust duct provided on the upper part of the battery pack.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, there may be a case where a battery cell in which a smoke exhaust valve is provided on the side surface of the battery cell is housed in a battery pack. In such a case, if the exhaust duct is provided on the upper part of the battery pack, the distance between the smoke exhaust valve and the exhaust duct becomes large, so there is a risk that the smoke exhaust efficiency will decrease. There is a need to improve the smoke exhaust efficiency in a power storage device that houses a power storage cell in which a smoke exhaust valve is provided on the side surface of the power storage cell.

[0005] One object of the present disclosure is to improve the smoke exhaust efficiency in a power storage device that houses a power storage cell in which a cell smoke exhaust valve is provided on the side surface of the power storage cell.

Means for Solving the Problems

[0006] A power storage device according to a certain aspect of the present disclosure comprises a plurality of power storage cells and a housing case housing the plurality of power storage cells. Each of the plurality of power storage cells includes a cell fume valve provided on the side of the power storage cell for exhausting gas from within the power storage cell. The housing case includes a lower case, an upper case, and a case fume valve for exhausting gas from within the housing case. The case fume valve is located above or below the center of the housing case in the vertical direction. If the case fume valve is located above the center of the housing case, the cell fume valve is located above the center of the power storage cell in the vertical direction. If the case fume valve is located below the center of the housing case, the cell fume valve is located below the center of the power storage cell in the vertical direction.

[0007] Preferably, the case exhaust valve is located above the center of the lower case or in the upper case, and the cell exhaust valve is located above the center of the energy storage cell in the vertical direction.

[0008] Preferably, the case exhaust valve is located below the center of the lower case, and the cell exhaust valve is located below the center of the energy storage cell in the vertical direction.

[0009] Preferably, the energy storage device is mounted on a vehicle. Each of the multiple energy storage cells includes a top surface, a bottom surface, a pair of short sides, and a pair of long sides. The pair of long sides are spaced apart in the width direction of the vehicle. Each of the pair of long sides is formed to extend in the longitudinal direction of the vehicle. The pair of short sides are spaced apart in the longitudinal direction of the vehicle. A cell exhaust valve is provided on one of the pair of short sides.

[0010] Preferably, the energy storage device is mounted on a vehicle. Each of the multiple energy storage cells includes a top surface, a bottom surface, a pair of short sides, and a pair of long sides. The pair of long sides are spaced apart in the longitudinal direction of the vehicle. Each of the pair of long sides is formed to extend in the width direction of the vehicle. The pair of short sides are spaced apart in the width direction of the vehicle. A cell exhaust valve is provided on one of the pair of short sides.

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

[0012] According to this disclosure, smoke exhaust efficiency is improved in an energy storage device that houses energy storage cells, in which a cell smoke exhaust valve is provided on the side of the energy storage cell. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic perspective view showing the energy storage device according to Embodiment 1. [Figure 2] This diagram schematically shows an example of an energy storage cell 10. [Figure 3] This diagram schematically shows a cross-section of the energy storage device 1 when it is cut by a plane parallel to the short side surface 13 of the energy storage cell 10, passing through the case smoke exhaust valve 23. [Figure 4] This is a schematic perspective view showing the energy storage device according to Embodiment 2. [Figure 5] This is a schematic perspective view showing the energy storage device according to Embodiment 3. [Figure 6] This diagram schematically shows an example of a 10B energy storage cell. [Figure 7] This is a schematic perspective view showing the energy storage device according to Embodiment 4. [Figure 8] This is a schematic cross-sectional view showing an energy storage device according to Embodiment 4. [Modes for carrying out the invention]

[0014] Hereinafter, embodiments and modifications according to the present disclosure will be described while referring 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] Referring to FIGS. 1 to 3, a power storage device according to Embodiment 1 will be described. FIG. 1 is a perspective view schematically showing the power storage device according to Embodiment 1.

[0016] Referring to FIG. 1, the power storage device 1 according to Embodiment 1 is used, for example, when mounted on a vehicle. 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 power storage cell 10 is a secondary battery, and typically a lithium ion secondary battery. The lithium ion secondary battery is a battery having lithium as a charge carrier, and may include a so-called all-solid-state battery using a solid electrolyte in addition to a general lithium ion secondary battery having a liquid electrolyte. Note that the power storage cell 10 is not limited to a lithium ion secondary battery, and may be configured by a nickel metal hydride secondary battery or other secondary batteries.

[0018] The power storage cells 10 are arranged so as to extend in the longitudinal direction D1 of the vehicle. Further, the plurality of power storage cells 10 are arranged along the width direction D2 of the vehicle.

[0019] The housing case 20 includes an upper case 21, a lower case 22, and a case exhaust valve 23. The lower case 22 includes a bottom plate, a peripheral wall, and a plurality of partition walls 60, 61, 62, 63, 64. The plurality of partition walls 60, 61, 62, 63, 64 partition the space inside the housing case 20 into a plurality of parts. [[ID=2�]]

[0020] The base plate is formed in a flat shape. The peripheral wall is formed to extend upward from the outer edge of the base plate, and the peripheral wall is formed in an annular shape. Partition walls 60, 61, 62, 63, and 64 are provided on the base plate. Partition walls 60, 61, 62, and 63 are formed to extend in the longitudinal 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 located in the center of the longitudinal direction D1 of the vehicle. Partition walls 60 and 63 are located in the center of the width direction D2 of the vehicle. Partition wall 60 is located in front of partition wall 64, and partition wall 63 is located behind partition wall 64. Multiple energy storage cells 10 are housed in the space formed when the upper case 21 is assembled to the lower case 22. Figure 1 shows the energy storage device 1 with the upper case 21 removed.

[0021] The case exhaust valve 23 is configured to discharge gas from inside the housing case 20. The case exhaust valve 23 is located in the upper case 21.

[0022] Figure 2 is a schematic diagram showing an example of a power storage cell 10. Referring to Figure 2, the power storage cell 10 includes a top surface 11, a bottom surface 12, a pair of short sides 13 and 14, and a pair of long sides 15 and 16. The pair of short sides 13 and 14 are spaced apart in the longitudinal direction D1 of the vehicle. The pair of long sides 15 and 16 are spaced apart in the width direction D2 of the vehicle. Each of the pair of long sides 15 and 16 is formed to extend in the longitudinal direction D1 of the vehicle. The short sides 13 and 14 and the long sides 15 and 16 are referred to as "sides" in this disclosure.

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

[0024] The energy storage cell 10 further includes a cell smoke exhaust valve 19 for exhausting gas from within the energy storage cell 10. The cell smoke exhaust valve 19 is configured to discharge gas from 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 rises. The gas discharged from the cell smoke exhaust valve 19 is hot. The cell smoke exhaust valve 19 is located on the side of the energy storage cell 10. More specifically, the cell smoke exhaust valve 19 is located on one of a pair of short sides 13, 14. In the example shown in Figure 2, the cell smoke exhaust valve 19 is located on the short side 13 where the negative electrode terminal 18 is located. The dashed line 71 indicates the central position of the energy storage cell 10 in the vertical direction D3 of the energy storage device 1 (see Figure 1). The cell smoke exhaust valve 19 is located above the center of the energy storage cell 10 in the vertical direction D3 of the energy storage device 1.

[0025] Figure 3 schematically shows a cross-section of the energy storage device 1 when it is cut through the case smoke exhaust valve 23 and parallel to the short side surface 13 of the energy storage cell 10. Note that in Figure 3, the hatching indicating the cross-section of the energy storage cell 10 has been omitted for the sake of readability.

[0026] Referring to Figure 3, the dashed line 72 indicates the central position of the housing case 20 in the vertical direction D3 of the energy storage device 1. As shown in Figure 3, the case exhaust valve 23 is located above the center of the housing case 20 in the vertical direction D3 of the energy storage device 1.

[0027] The lower surface 12 of the energy storage cell 10 and the lower case 22 are fixed together by adhesive 30. The energy storage device 1 further includes a cooler 40 for cooling the energy storage cell 10. The cooler 40 is mounted on top of the energy storage cell 10. More specifically, the cooler 40 is mounted along the upper surface 11 in the space between the upper surface 11 of the energy storage cell 10 and the upper case 21. This positions the cooler 40 near the cell exhaust valve 19 (see Figure 2).

[0028] A space 50 is provided between the upper surface 11 of the energy storage cell 10 and the upper case 21, where the cooler 40 is not installed. The space 50 includes at least a portion 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 exhaust valve 19 (see Figure 2), the cooler 40, the space 50, and the case exhaust valve 23 are located above the center of the housing case 20 in the vertical direction D3 of the energy storage device 1. The gas discharged from the cell exhaust valve 19 (see Figure 2) moves along the short side 13 (see Figure 2) inside the housing case 20 and reaches the vicinity of the cooler 40. When the housing case 20 is filled with gas, the internal pressure inside the housing case 20 increases. As a result, the upper case 21 deforms so that it bulges upward. On the other hand, since the lower case 22 and each energy storage cell 10 are fixed by adhesive 30, deformation of the lower case 22 is suppressed. As the upper case 21 deforms so that it bulges upward, a gap is formed between the upper case 21 and the cooler 40, and gas accumulates in this gap.

[0030] Subsequently, when the internal pressure inside the containment case 20 exceeds a predetermined pressure, the case smoke exhaust valve 23 opens, and the gas inside the containment case 20 is discharged to the outside. At this time, the case smoke exhaust valve 23 is located in the upper case 21, and the gas is also accumulated between the upper case 21 and the cooler 40, so the gas is efficiently exhausted to the outside through the case smoke exhaust valve 23. Specifically, the gas discharged from the cell smoke exhaust valve 19 moves through the gap to the space 50, and then is discharged from the case smoke exhaust valve 23 to the outside of the containment case 20 through the space 50. Therefore, with the energy storage device 1, the smoke exhaust efficiency of discharging the gas discharged from the cell smoke exhaust valve 19 to the outside of the containment case 20 through the case smoke exhaust valve 23 is improved.

[0031] Here, the gas discharged from the cell exhaust valve 19 is at a high temperature, and as described above, the gas accumulates at the top within the housing case 20. On the other hand, a cooler 40 is placed on the upper surface 11 of each energy storage cell 10, so that the upper surface 11 of each energy storage cell 10 does not deteriorate due to the heat from the high-temperature gas. In addition, a partition wall 60 is located below the space 50, so that the energy storage cells 10 are not exposed to the high-temperature gas as the gas flows through the space 50.

[0032] Furthermore, in the energy storage device 1, the cooler 40 is located near the cell exhaust valve 19. Therefore, according to the energy storage device 1, the gas discharged from the cell exhaust valve 19 is cooled relatively quickly. Also, in the energy storage device 1, the cooler 40 is located in the path of the gas discharged from the cell exhaust valve 19. Therefore, the gas discharged from the cell exhaust valve 19 is gradually cooled as it approaches the case exhaust valve 23. Therefore, according to the energy storage device 1, damage to the energy storage cell 10 and the upper case 21 by the high-temperature gas discharged from the cell exhaust valve 19 is suppressed.

[0033] As described above, in the energy storage device 1 according to Embodiment 1, the case smoke exhaust valve 23 is located above the center of the housing case 20 in the vertical direction D3 of the energy storage device 1, and the cell smoke exhaust valve 19 is located above the center of the energy storage cell 10 in the vertical direction D3 of the energy storage device 1. With this configuration, the smoke exhaust path that the gas discharged from the cell smoke exhaust valve 19 travels through to be discharged outside the housing case 20 from the case smoke exhaust valve 23 can be shortened compared to when the cell smoke exhaust valve 19 is located below the center of the energy storage cell 10 in the vertical direction D3 of the energy storage device 1. Therefore, according to the energy storage device 1 according to Embodiment 1, when the cell smoke exhaust valve 19 is located on the side of the energy storage cell 10, the smoke exhaust efficiency of discharging the gas discharged from the cell smoke exhaust valve 19 to the outside of the housing case 20 from the case smoke exhaust valve 23 is improved. Furthermore, according to the energy storage device 1 of Embodiment 1, the exhaust gas path can be shortened, thereby reducing the contact area between the high-temperature gas discharged from the cell exhaust valve 19 and the energy storage cell 10.

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

[0035] Furthermore, in the energy storage device 1 according to Embodiment 1, the lower surface 12 of the energy storage cell 10 and the lower case 22 are fixed together by adhesive 30. In the energy storage device 1 according to Embodiment 1, with the above configuration, the gas discharged from the cell exhaust valve 19 rises along the short side 13 inside the housing case 20, passes through the space 50, and is discharged outside the housing case 20 from the case exhaust valve 23. Therefore, according to the energy storage device 1 according to Embodiment 1, it is possible to suppress contact between the high-temperature gas discharged from the cell exhaust valve 19 and the adhesive 30.

[0036] [Embodiment 2] The energy storage device according to Embodiment 2 will be described with reference to Figure 4. Figure 4 is a schematic perspective view showing the energy storage device according to Embodiment 2.

[0037] Referring to Figure 4, the difference between the energy storage device 1A according to Embodiment 2 and the energy storage device 1 according to Embodiment 1 (see Figure 1) is the position of the case smoke exhaust valve 23. In the energy storage device 1A according to Embodiment 2, the case smoke exhaust valve 23 is provided in the lower case 22. As other points are the same as those of the energy storage device 1A according to Embodiment 1 (see Figure 1), we will not repeat the explanation.

[0038] Figure 4 shows the energy storage device 1A with the upper case 21 removed. The dashed line 73 indicates the position of the center of the housing case 20 in the vertical direction D3 of the energy storage device 1A. In the energy storage device 1A, the case smoke exhaust valve 23 is located above the center of the housing case 20 in the vertical direction D3 of the energy storage device 1A. That is, in the energy storage device 1A, the case smoke exhaust valve 23 is located above the center of the lower case 22 in the vertical direction D3 of the energy storage device 1A. The gas discharged from the cell smoke exhaust valve 19 (see Figure 2) moves along the short side 13 (see Figure 2) and is discharged outside the housing case 20 from the case smoke exhaust valve 23 (see Figure 4).

[0039] Thus, in the energy storage device 1A according to Embodiment 2, the case smoke exhaust valve 23 is located above the center of the housing case 20 in the vertical direction D3 of the energy storage device 1A, and the cell smoke exhaust valve 19 is located above the center of the energy storage cell 10 in the vertical direction D3 of the energy storage device 1A. With this configuration, the smoke exhaust path that the gas discharged from the cell smoke exhaust valve 19 travels through to be discharged outside the housing case 20 from the case smoke exhaust valve 23 can be shortened compared to the case where the cell smoke exhaust valve 19 is located below the center of the energy storage cell 10 in the vertical direction D3 of the energy storage device 1A. Therefore, according to the energy storage device 1A according to Embodiment 2, when the cell smoke exhaust valve 19 is located on the side of the energy storage cell 10, the smoke exhaust efficiency of discharging the gas discharged from the cell smoke exhaust valve 19 to the outside of the housing case 20 from the case smoke exhaust valve 23 is improved. Furthermore, according to the energy storage device 1A of Embodiment 2, the exhaust gas path can be shortened, thereby reducing the contact area between the high-temperature gas discharged from the cell exhaust valve 19 and the energy storage cell 10.

[0040] Furthermore, in the energy storage device 1A according to Embodiment 2, the cell exhaust valve 19 is provided on one of the pair of short sides 13 and 14 of the energy storage cell 10 (for example, the short side 13). With this configuration, the gas discharged from the cell exhaust valve 19 moves along the short side 13 and is discharged outside the housing case 20 from the case exhaust valve 23. If the cell exhaust valve 19 is provided on one of the pair of long sides 15 and 16 of the energy storage cell 10, the gas discharged from the cell exhaust valve 19 moves inside the housing case 20 along the long side 15 or long side 16. Therefore, if the cell exhaust valve 19 is provided on one of the pair of long sides 15 and 16 of the energy storage cell 10, the area in contact with the energy storage cell 10 by the high-temperature gas discharged from the cell exhaust valve 19 becomes larger. However, in the energy storage device 1A according to Embodiment 2, the cell exhaust valve 19 is provided on one of the pair of short sides 13 and 14 of the energy storage cell 10. Therefore, according to the energy storage device 1A according to Embodiment 2, the area in which the high-temperature gas discharged from the cell exhaust valve 19 comes into contact with the energy storage cell 10 can be reduced compared to the case where the cell exhaust valve 19 is provided on one of the pair of long sides 15 and 16 of the energy storage cell 10.

[0041] Furthermore, in the energy storage device 1A according to Embodiment 2, the lower surface 12 of the energy storage cell 10 and the lower case 22 are fixed together by adhesive 30. In the energy storage device 1A according to Embodiment 2, with the above configuration, the gas discharged from the cell exhaust valve 19 moves along the short side 13 and is discharged outside the housing case 20 from the case exhaust valve 23. Therefore, according to the energy storage device 1A according to Embodiment 2, it is possible to suppress contact between the high-temperature gas discharged from the cell exhaust valve 19 and the adhesive 30.

[0042] [Embodiment 3] The energy storage device according to Embodiment 3 will be described with reference to Figures 5 and 6. Figure 5 is a schematic perspective view showing the energy storage device according to Embodiment 3.

[0043] Referring to Figure 5, the energy storage device 1B according to Embodiment 3 differs from the energy storage device 1 according to Embodiment 1 (see Figure 1) in two respects. The first difference is that the energy storage device 1B according to Embodiment 3 is equipped with multiple energy storage cells 10B instead of multiple energy storage cells 10 (see Figure 1). The second difference is the location of the case smoke exhaust valve 23. In the energy storage device 1B according to Embodiment 3, the case smoke exhaust valve 23 is provided in the lower case 22. As other points are the same as those of the energy storage device 1B according to Embodiment 3 (see Figure 1), we will not repeat the explanation.

[0044] Figure 5 shows the energy storage device 1B with the upper case 21 removed. Multiple energy storage cells 10B are housed in a housing case 20. The energy storage cells 10B are arranged to extend in the longitudinal direction D1 of the vehicle. In addition, the multiple energy storage cells 10B are arranged along the width direction D2 of the vehicle.

[0045] The dashed line 74 indicates the central position of the lower case 22 in the vertical direction D3 of the energy storage device 1B. In the energy storage device 1B, the case smoke exhaust valve 23 is located below the center of the lower case 22 in the vertical direction D3 of the energy storage device 1B. That is, in the energy storage device 1B, the case smoke exhaust valve 23 is located below the center of the housing case 20 in the vertical direction D3 of the energy storage device 1B.

[0046] Figure 6 is a schematic diagram showing an example of a storage cell 10B. The difference between storage cell 10B and the storage cell 10 (see Figure 2) described above is the position of the cell smoke exhaust valve 19 and the negative electrode terminal 18. As other aspects are the same as those of storage cell 10 (see Figure 2), we will not repeat the explanation.

[0047] The cell smoke exhaust valve 19 is located on the side of the energy storage cell 10B. More specifically, the cell smoke exhaust valve 19 is located on one of a pair of short sides 13 and 14. In the example shown in Figure 6, the cell smoke exhaust valve 19 is located on the short side 13 where the negative electrode terminal 18 is located. The dashed line 75 indicates the central position of the energy storage cell 10B in the vertical direction D3 of the energy storage device 1B (see Figure 5). The cell smoke exhaust valve 19 is located 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 located on the short side 13 in a position that does not overlap with the cell smoke exhaust valve 19.

[0048] Furthermore, both the positive terminal 17 and the negative terminal 18 may be provided on one of the pair of short sides 13 and 14.

[0049] Thus, in the energy storage device 1B according to Embodiment 3, the case smoke exhaust valve 23 is located below the center of the housing case 20 in the vertical direction D3 of the energy storage device 1B, and the cell smoke exhaust valve 19 is located below the center of the energy storage cell 10B in the vertical direction D3 of the energy storage device 1B. With this configuration, the smoke exhaust path that the gas discharged from the cell smoke exhaust valve 19 travels through to be discharged outside the housing case 20 from the case smoke exhaust valve 23 can be shortened compared to the case where the cell smoke exhaust valve 19 is located above the center of the energy storage cell 10B in the vertical direction D3 of the energy storage device 1B. Therefore, according to the energy storage device 1B according to Embodiment 3, when the cell smoke exhaust valve 19 is located on the side of the energy storage cell 10B, the smoke exhaust efficiency of discharging the gas discharged from the cell smoke exhaust valve 19 to the outside of the housing case 20 from the case smoke exhaust valve 23 is improved. Furthermore, according to the energy storage device 1B of Embodiment 3, the exhaust gas path can be shortened, thereby reducing the contact area between the high-temperature gas discharged from the cell exhaust valve 19 and the energy storage cell 10B.

[0050] Furthermore, in the energy storage device 1B according to Embodiment 3, the cell smoke exhaust valve 19 is provided on one of the pair of short sides 13 and 14 of the energy storage cell 10B (for example, the short side 13). With this configuration, the gas discharged from the cell smoke exhaust valve 19 moves along the short side 13 and is discharged outside the housing case 20 from the case smoke exhaust valve 23. If the cell smoke exhaust valve 19 is provided on one of the pair of long sides 15 and 16 of the energy storage cell 10B, the gas discharged from the cell smoke exhaust valve 19 moves inside the housing case 20 along the long side 15 or long side 16. Therefore, if the cell smoke exhaust valve 19 is provided on one of the pair of long sides 15 and 16 of the energy storage cell 10B, the area in contact with the energy storage cell 10B by the high-temperature gas discharged from the cell smoke exhaust valve 19 becomes larger. However, in the energy storage device 1B according to Embodiment 3, the cell exhaust valve 19 is provided on one of the pair of short sides 13 and 14 of the energy storage cell 10B. Therefore, according to the energy storage device 1B according to Embodiment 3, the area in which the high-temperature gas discharged from the cell exhaust valve 19 comes into contact with the energy storage cell 10B can be reduced compared to the case where the cell exhaust valve 19 is provided on one of the pair of long sides 15 and 16 of the energy storage cell 10B.

[0051] Furthermore, in the energy storage device 1B according to Embodiment 3, the lower surface 12 of the energy storage cell 10B and the lower case 22 are fixed together by adhesive 30. In the energy storage device 1B according to Embodiment 3, with the above configuration, the gas discharged from the cell exhaust valve 19 moves along the short side 13 and is discharged outside the housing case 20 from the case exhaust valve 23. Therefore, according to the energy storage device 1B according to Embodiment 3, it is possible to suppress contact between the high-temperature gas discharged from the cell exhaust valve 19 and the adhesive 30.

[0052] [Embodiment 4] The energy storage device according to Embodiment 4 will be described with reference to Figures 7, 8, and 2. Figure 7 is a schematic perspective view showing the energy storage device according to Embodiment 4. Figure 8 is a schematic cross-sectional view showing the energy storage device according to Embodiment 4.

[0053] Referring to Figure 7, the difference between the energy storage device 1C according to Embodiment 4 and the energy storage device 1 according to Embodiment 1 (see Figure 1) is the arrangement of the energy storage cells 10. In the energy storage device 1C according to Embodiment 4, the energy storage cells 10 are arranged to extend in the width direction D2 of the vehicle, and multiple energy storage cells 10 are arranged along the longitudinal direction D1 of the vehicle. In other respects, the energy storage device 1C according to Embodiment 4 is the same as the energy storage device 1 according to Embodiment 1 (see Figure 1).

[0054] Referring to Figure 8, Figure 8 schematically shows a cross-section of the energy storage device 1C when it is cut through the case smoke exhaust valve 23 and parallel to the long side surface 16 of the energy storage cell 10. Note that in Figure 8, for the sake of readability, the hatching showing the cross-sections of the energy storage cell 10, the cell smoke exhaust valve 19, the positive terminal 17, and the negative terminal 18 has been omitted.

[0055] Referring to Figures 2 and 8, in the energy storage device 1C according to Embodiment 4, a pair of short sides 13 and 14 of the energy storage cell 10 are spaced apart in the vehicle width direction D2, and a pair of long sides 15 and 16 are spaced apart in the vehicle front-rear direction D1. In addition, in the energy storage device 1C according to Embodiment 4, each of the pair of long sides 15 and 16 is formed to extend in the vehicle width direction D2. Also in the energy storage device 1C according to Embodiment 4, the cell exhaust valve 19 is provided on one of the pair of short sides 13 and 14. In the example shown in Figures 2 and 8, the cell exhaust valve 19 is provided on the short side 13.

[0056] Referring to Figure 8, the dashed line 76 indicates the central position of the housing case 20 in the vertical direction D3 of the energy storage device 1C. The case exhaust valve 23 is located above the center of the housing case 20 in the vertical direction D3 of the energy storage device 1C. That is, the case exhaust valve 23 is located above the center of the lower case 22 in the vertical direction D3 of the energy storage device 1C. In addition, the cell exhaust valve 19 is located above the center of the energy storage cell 10 in the vertical direction D3 of the energy storage device 1C.

[0057] Furthermore, the energy storage device 1C, like the energy storage device 1 (see Figure 1), includes a cooler 40 for cooling the energy storage cell 10. The cooler 40 is mounted on top of the energy storage cell 10. More specifically, the cooler 40 is mounted along the top surface 11 in the space between the top surface 11 of the energy storage cell 10 and the upper case 21. As a result, the cooler 40 is located near the cell exhaust valve 19.

[0058] A space 50 is provided between the upper surface 11 of the energy storage cell 10 and the upper case 21, where the cooler 40 is not installed. The space 50 includes at least a portion of the area facing the case smoke exhaust valve 23. The lower surface 12 of the energy storage cell 10 and the lower case 22 are fixed together by adhesive 30.

[0059] Thus, in the energy storage device 1C, the cell exhaust valve 19, the cooler 40, the space 50, and the case exhaust valve 23 are located above the center of the housing case 20 in the vertical direction D3 of the energy storage device 1C. Therefore, in the energy storage device 1C, as with the energy storage device 1 described above, gas can be effectively exhausted to the outside through the case exhaust valve 23.

[0060] Furthermore, in the energy storage device 1C, a cooler 40 is placed on the upper surface 11 of each energy storage cell 10, which helps to suppress deterioration of the upper surface 11 of each energy storage cell 10 due to heat from high-temperature gas.

[0061] Furthermore, in the energy storage device 1C, the case smoke exhaust valve 23 is located above the center of the housing case 20 in the vertical direction D3 of the energy storage device 1C, and the cell smoke exhaust valve 19 is located above the center of the energy storage cell 10 in the vertical direction D3 of the energy storage device 1C. Therefore, the smoke exhaust path that the gas discharged from the cell smoke exhaust valve 19 travels through to be discharged outside the housing case 20 from the case smoke exhaust valve 23 can be shortened.

[0062] [Example 1] Referring to Figure 8, in the energy storage device 1C, the cell exhaust valve 19, the cooler 40, the space 50, and the case exhaust valve 23 may be located below the center of the housing case 20 in the vertical direction D3 of the energy storage device 1C. The specific configuration of the energy storage device in such a case is as follows.

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

[0064] In this type of energy storage device, when the gas discharged from the cell smoke exhaust valve 19 fills the storage case 20, the lower case 22 deforms, creating a gap between the lower case 22 and the cooler 40, where the gas accumulates. Subsequently, when the internal pressure in the storage case 20 exceeds a predetermined pressure, the case smoke exhaust valve 23 opens, and the gas in the storage case 20 is discharged to the outside. At this time, since the case smoke exhaust valve 23 is located in the lower case 22, and the gas is also accumulated between the lower case 22 and the cooler 40, the gas is efficiently exhausted to the outside through the case smoke exhaust valve 23. Therefore, the same effects as in energy storage device 1C are achieved in this type of energy storage device.

[0065] Furthermore, this configuration may also be applied to the energy storage device 1 (see Figure 3). In that case, the same effects as those of the energy storage device 1 will be achieved.

[0066] [Differentiation 2] In the energy storage device 1A according to Embodiment 2, the energy storage cells 10 may be arranged to extend in the vehicle width direction D2, and a plurality of energy storage cells 10 may be arranged along the vehicle's longitudinal direction D1. Referring to Figure 2, in this case, a pair of short sides 13 and 14 of the energy storage cell 10 are spaced apart in the vehicle width direction D2, and a pair of long sides 15 and 16 are spaced apart in the vehicle's longitudinal direction D1. Furthermore, each of the pair of long sides 15 and 16 is formed to extend in the vehicle width direction D2. In addition, the cell exhaust valve 19 is provided on one of the pair of short sides 13 and 14. Even in this case, the same effects as those described in Embodiment 2 are achieved.

[0067] Furthermore, in the energy storage device 1B according to Embodiment 3, the energy storage cells 10B may be arranged to extend in the vehicle width direction D2, and a plurality of energy storage cells 10B may be arranged along the vehicle longitudinal direction D1. Referring to Figure 6, in this case, a pair of short sides 13, 14 of the energy storage cell 10B are provided at intervals in the vehicle width direction D2, and a pair of long sides 15, 16 are arranged at intervals in the vehicle longitudinal direction D1. Also, each of the pair of long sides 15, 16 is formed to extend in the vehicle width direction D2. In addition, the cell exhaust valve 19 is provided on one of the pair of short sides 13, 14. Even in this case, the same effects as those described in Embodiment 3 are achieved.

[0068] [Difference 3] Referring to Figure 2, the cell exhaust valve 19 may be provided on one of the pair of long sides 15, 16 of the energy storage cell 10. Also, referring to Figure 6, the cell exhaust valve 19 may be provided on one of the pair of long sides 15, 16 of the energy storage cell 10B.

[0069] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended. [Explanation of Symbols]

[0070] 1,1A,1B,1C Energy storage device, 10,10B Energy storage cell, 11 Top view, 12 Bottom view, 13,14 Short side view, 15,16 Long side view, 17 Positive terminal, 18 Negative terminal, 19 Cell exhaust valve, 20 Housing case, 21 Upper case, 22 Lower case, 23 Case exhaust valve, 30 Adhesive, 40 Cooler, 50 Space, 60,61,62,63,64 Partition wall, 71,72,73,74,75 Dotted line, D1 Front-to-back direction, D2 Width direction, D3 Up-and-down direction.

Claims

1. A power storage device, Multiple energy storage cells, A peripheral wall surrounding the plurality of energy storage cells, A smoke exhaust valve provided on the peripheral wall, The system comprises a cooler positioned above the plurality of energy storage cells, The peripheral wall includes a first wall portion and a second wall portion arranged in the front-rear direction of the energy storage device. The smoke exhaust valve is provided above the center of the first wall portion in the vertical direction of the energy storage device. The plurality of energy storage cells are arranged to extend in the front-to-back direction, Each of the aforementioned plurality of energy storage cells is The energy storage device is arranged with a gap in the width direction, and has a pair of long sides that extend in the front-rear direction, It includes a first short side and a second short side arranged at intervals in the front-rear direction, The first short side faces the first wall, Each of the plurality of energy storage cells includes a cell smoke exhaust valve, The cell exhaust valve is a power storage device provided above the center of the first short side in the vertical direction.

2. The energy storage device according to claim 1, wherein in all of the plurality of energy storage cells, the cell exhaust valve is provided above the center of the first short side in the vertical direction.

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