Power storage device

Abstract

Suppresses thermal runaway of the storage module. [Solution] The energy storage device includes an energy storage module 10a, an energy storage module 10b, and a reinforcing member 82 arranged between the energy storage modules 10a and 10b. The reinforcing member 82 includes a first wall portion 821 facing the energy storage module 10a and a second wall portion 822 facing the energy storage module 10b. A hollow portion P1 is formed between the first wall portion 821 and the second wall portion 822. A first space Q1 is formed between the energy storage module 10a and the reinforcing member 82. A first hole portion 831 connecting the first space Q1 and the hollow portion P1 is formed in the first wall portion 821. A second space Q2 is formed between the energy storage module 10b and the reinforcing member 82. A second hole portion connecting the second space Q2 and the hollow portion P1 is formed in the second wall portion 822.

Description

[Technical Field]

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

[0002] For example, Japanese Patent Application Laid-Open No. 2024-080096 discloses an energy storage device including two energy storage modules and a case that houses the two energy storage modules. Each of the two energy storage modules is disposed in an area defined by a bottom wall, a peripheral wall, and a cross member (reinforcing member). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2024-080096 Summary of the Invention [Problem to be solved by the invention]

[0004] The energy storage module is formed with a smoke exhaust section for discharging gas inside the energy storage module when the internal pressure of the energy storage module increases. The gas contains conductive foreign matter (debris). If the energy storage module is placed in an area partitioned by a reinforcing member or the like, the gas discharged from the energy storage module will remain in the area, causing the conductive foreign matter to accumulate in the area. If the conductive foreign matter accumulates in the area where the energy storage module is placed, the thermal effect from the conductive foreign matter will cause thermal runaway of the energy storage module.

[0005] An object of the present disclosure is to suppress thermal runaway in an electricity storage module. [Means for solving the problem]

[0006] An energy storage device according to an aspect of the present disclosure includes a first energy storage module, a second energy storage module adjacent to the first energy storage module, and a reinforcing member disposed between the first and second energy storage modules. A smoke exhaust section for exhausting gas from the first energy storage module is formed below the center of the first energy storage module in the up-down direction. The reinforcing member includes a first wall section facing the first energy storage module and a second wall section facing the second energy storage module. A hollow section is formed between the first wall section and the second wall section. A first space is formed between the first energy storage module and the reinforcing member. A first hole section is formed in the first wall section, connecting the first space and the hollow section. A second space is formed between the second energy storage module and the reinforcing member. A second hole section is formed in the second wall section, connecting the second space and the hollow section.

[0007] Preferably, each of the first hole portion and the second hole portion is formed below the center of the reinforcing member in the up-down direction.

[0008] Preferably, the energy storage device further includes an upper case and a lower case, and a housing case that houses the first energy storage module and the second energy storage module. The reinforcing member passes between the first energy storage module and the second energy storage module and extends along the bottom wall of the lower case. The positions of the first hole and the second hole are offset in the extending direction of the reinforcing member. [Effects of the Invention]

[0009] According to the present disclosure, thermal runaway of the power storage module can be suppressed. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic exploded perspective view of a power storage device according to an embodiment of the present disclosure. [Figure 2] 2 is a view of the inside of the power storage device 100 viewed from above the power storage device 100 shown in FIG. 1 with an upper case 91 removed. [Figure 3]FIG. 2 is a diagram schematically illustrating the power storage unit 110 shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 3 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments and modifications according to the present disclosure will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals, and the description thereof will not be repeated. Note that the embodiments and modifications described below may be selectively combined as appropriate.

[0012] [Embodiment] Fig. 1 is a diagram schematically illustrating an exploded perspective view of a power storage device according to an embodiment of the present disclosure. Fig. 2 is a diagram illustrating the interior of the power storage device 100 viewed from above the power storage device 100 with an upper case 91 removed from the power storage device 100 shown in Fig. 1. Fig. 3 is a diagram schematically illustrating the power storage unit 110 shown in Fig. 1. Note that, in consideration of ease of viewing the drawing, a smoke exhaust section 152 is omitted from Fig. 1. Also, in consideration of ease of viewing the drawing, a reinforcing member 81 and a cooler 30 are hatched in Fig. 2.

[0013] 1 and 2, the power storage device 100 in this embodiment is, for example, a battery pack. As an example, the power storage device 100 is mounted on a vehicle. The vehicle runs using the power stored in the power storage device 100. Examples of the vehicle include a hybrid vehicle, a plug-in hybrid vehicle, a fuel cell vehicle, and an electric vehicle. Note that the use of the power storage device 100 is not limited to vehicle use. The power storage device 100 may also be mounted on a device other than a vehicle and store power for driving the device.

[0014] In the present disclosure, the X direction, Y direction, and Z direction are perpendicular to one another. When the power storage device 100 is mounted on a vehicle, for example, the X direction is the front-to-rear direction of the vehicle, and the Y direction is the width direction of the vehicle. The X1 direction is the direction from the rear side of the vehicle to the front side of the vehicle. The X2 direction is the direction from the front side of the vehicle to the rear side of the vehicle. The Y1 direction is the direction from the right side of the vehicle to the left side of the vehicle. The Y2 direction is the direction from the left side of the vehicle to the right side of the vehicle. The Z direction is the up-down (vertical) direction. The Z1 direction is the direction from the bottom side of the vehicle to the top side of the vehicle. The Z2 direction is the direction from the top side of the vehicle to the bottom side of the vehicle. In the present disclosure, the Z1 direction is also referred to as the upward direction, and the Z2 direction is also referred to as the downward direction.

[0015] The electricity storage device 100 includes a storage case 90, a plurality of reinforcing members 81, a plurality of reinforcing members 82, an electricity storage unit 110, a plurality of coolers 30, cooling pipes 41, 42, a plurality of brackets 60, and a plurality of brackets 70.

[0016] The accommodation case 90 accommodates a plurality of reinforcing members 81, a plurality of reinforcing members 82, the power storage unit 110, a plurality of coolers 30, the cooling pipes 41 and 42, a plurality of brackets 60, and a plurality of brackets 70. More specifically, the accommodation case 90 includes an upper case 91 and a lower case 92. The lower case 92 is disposed below the upper case 91. The periphery of the upper case 91 is connected to the periphery of the lower case 92 by bolts or the like via a sealing member. The space formed by the upper case 91 and the lower case 92 accommodates the plurality of reinforcing members 81, a plurality of reinforcing members 82, the power storage unit 110, the plurality of coolers 30, the cooling pipes 41 and 42, the plurality of brackets 60, and the plurality of brackets 70.

[0017] The lower case 92 includes a bottom wall 921 and a peripheral wall 922. The peripheral wall 922 stands upright from the peripheral edge of the bottom wall 921. The peripheral wall 922 is formed in a substantially rectangular cylindrical shape. The peripheral wall 922 includes side walls 931 to 934. The side walls 931 and 932 are spaced apart in the Y direction. The side wall 932 is located on the Y2 side of the side wall 931. The side walls 933 and 934 are spaced apart in the X direction. The side wall 934 is located on the X2 side of the side wall 933.

[0018] Reinforcing members 81 and 82 are provided on lower case 92. Each of reinforcing members 81 and 82 is formed so as to protrude upward from bottom wall 921 of lower case 92. Each of reinforcing members 81 and 82 is fixed (for example, fastened or welded) to bottom wall 921. Each of reinforcing members 81 and 82 is, for example, a plate-shaped member made of metal.

[0019] In this embodiment, the multiple reinforcing members 81 include four reinforcing members 81. The four reinforcing members 81 are arranged at intervals in the X direction. Each of the four reinforcing members 81 extends in the Y direction along the bottom wall 921 of the lower case 92. The number of reinforcing members 81 is not limited to four. It is sufficient that one or more reinforcing members 81 are provided in the lower case 92.

[0020] In this embodiment, the multiple reinforcing members 82 include six reinforcing members 82. More specifically, two reinforcing members 82 are arranged in the Y direction between the reinforcing members 81 aligned in the X direction. Each reinforcing member 82 extends in the X direction along the bottom wall 921 of the lower case 92. The number of reinforcing members 82 is not limited to six. It is sufficient that one or more reinforcing members 82 are provided in the lower case 92.

[0021] The accommodation space within the accommodation case 90 is divided into a plurality of regions (nine in this embodiment) by the plurality of reinforcing members 81 and the plurality of reinforcing members 82. One power storage module 10 is arranged in each of the nine regions.

[0022] The power storage unit 110 includes a plurality of power storage modules 10. In this embodiment, the plurality of power storage modules 10 includes nine power storage modules 10. The number of power storage modules 10 is not limited to nine. The power storage unit 110 may include two or more power storage modules 10.

[0023] The nine energy storage modules 10 are arranged in a 3 × 3 matrix on the XY plane. Specifically, three module rows M, each consisting of three energy storage modules 10 aligned in the Y direction, are arranged in the X direction.

[0024] Each module row M includes a power storage module 10a, a power storage module 10b, and a power storage module 10c. The power storage module 10a is the central storage module 10 of the three power storage modules 10 in the module row M. The power storage module 10b is the storage module 10 of the three power storage modules 10 in the module row M that is arranged closest to the Y2 side. The power storage module 10c is the storage module 10 of the three power storage modules 10 in the module row M that is arranged closest to the Y1 side. The power storage module 10a and the power storage module 10b are adjacent to each other in the horizontal direction (more specifically, the Y direction), and the power storage module 10a and the power storage module 10c are adjacent to each other in the horizontal direction (more specifically, the Y direction).

[0025] A reinforcing member 81 is arranged between adjacent module rows M in the X direction. More specifically, a reinforcing member 81 is arranged between adjacent power storage modules 10 in the X direction. A reinforcing member 82 is arranged between adjacent power storage modules 10 in the Y direction. The reinforcing member 82 passes between adjacent power storage modules 10 in the Y direction and extends along the bottom wall 921 of the lower case 92.

[0026] Each energy storage module 10 includes a lower module 1 and an upper module 2. The upper module 2 is disposed higher (on the Z1 side) than the lower module 1. The lower module 1 and the upper module 2 are stacked in the Z direction with the cooler 30 sandwiched between them. Note that each energy storage module 10 may include the lower module 1 but not the upper module 2.

[0027] Referring to FIG. 3 , a smoke exhaust section 151 that exhausts gas from within the power storage module 10 is formed below the center in the vertical direction of the power storage module 10. A smoke exhaust section 152 that exhausts gas from within the power storage module 10 is formed above the center in the vertical direction of the power storage module 10. More specifically, a smoke exhaust section 151 that exhausts gas from within the lower module 1 is formed on the bottom surface of each lower module 1. A smoke exhaust section 152 that exhausts gas from within the upper module 2 is formed on the top surface of each upper module 2. In this embodiment, each of the smoke exhaust sections 151 and 152 is a smoke exhaust port. In this embodiment, one smoke exhaust section 151 is formed in the lower module 1, and one smoke exhaust section 152 is formed in the upper module 2. In this embodiment, when viewed from above, the smoke exhaust section 151 has an elliptical shape. In this embodiment, when the smoke exhaust section 152 is viewed from above, the smoke exhaust section 152 has an elliptical shape.

[0028] The smoke exhaust section 151 only needs to be formed below the center of the power storage module 10 in the vertical direction, and does not have to be formed on the lower surface of the lower module 1. The number of smoke exhaust sections 151 formed in the power storage module 10 is not limited to one. The number of smoke exhaust sections 151 formed in the power storage module 10 may be one or more. The shape of the smoke exhaust section 151 formed in the power storage module 10 is not limited to the shape shown in FIG. 3.

[0029] Furthermore, the smoke exhaust section 152 only needs to be formed above the center of the power storage module 10 in the vertical direction, and does not need to be formed on the upper surface of the upper module 2. Furthermore, the number of smoke exhaust sections 152 formed in the power storage module 10 is not limited to one. The number of smoke exhaust sections 152 formed in the power storage module 10 may be one or more. Furthermore, the shape of the smoke exhaust section 152 formed in the power storage module 10 is not limited to the shape shown in FIG. 3.

[0030] Each of the lower module 1 and the upper module 2 includes a plurality of storage cells 13 (see FIG. 4) and a cell case 14 (see FIG. 4) that houses the plurality of storage cells 13. The plurality of storage cells 13 are arranged side by side in the X direction. The plurality of storage cells 13 may also be arranged side by side in the Y direction.

[0031] Each storage cell 13 is provided with a cell smoke exhaust valve for exhausting gas inside the storage cell 13 when the internal pressure of the storage cell 13 reaches or exceeds a predetermined value. Gas exhausted from each storage cell 13 in the lower module 1 is exhausted to the outside of the lower module 1 through a smoke exhaust section 151. Gas exhausted from each storage cell 13 in the upper module 2 is exhausted to the outside of the upper module 2 through a smoke exhaust section 152.

[0032] The nine energy storage modules 10 included in the energy storage unit 110 are connected in series by a plurality of first bus bars 21, a plurality of second bus bars 22, and a plurality of third bus bars 23. Each first bus bar 21 electrically connects the energy storage modules 10 aligned in the Y direction. Each second bus bar 22 electrically connects the lower module 1 and upper module 2 aligned in the vertical direction. Each third bus bar 23 electrically connects the module rows M aligned in the X direction.

[0033] 1 and 2, a cooler 30 is provided for each module row M. That is, in this embodiment, the plurality of coolers 30 includes three coolers 30. Each cooler 30 is disposed between a lower module 1 and an upper module 2. Each cooler 30 cools the three power storage modules 10 (power storage module 10a, power storage module 10b, and power storage module 10c) included in the module row M with refrigerant supplied from a cooling pipe 41.

[0034] The number of coolers 30 is not limited to 3. The number of coolers 30 can change depending on the number of module rows M. Furthermore, a cooler 30 may be provided for each power storage module 10.

[0035] The cooling pipes 41 are pipes through which the refrigerant supplied to each cooler 30 passes. The cooling pipes 42 are pipes through which the refrigerant discharged from each cooler 30 passes. Each of the cooling pipes 41 and 42 has a cylindrical shape.

[0036] Each of the brackets 60 and 70 is formed from aluminum, for example. Each of the brackets 60 and 70 is provided for each module row M. That is, in this embodiment, the plurality of brackets 60 includes three brackets 60, and the plurality of brackets 70 includes three brackets 70. Note that the number of each of the brackets 60 and 70 is not limited to three. The number of each of the brackets 60 and 70 can vary depending on the number of module rows M.

[0037] Each of the brackets 60 and 70 connects the three power storage modules 10 (power storage module 10a, power storage module 10b, and power storage module 10c) of the module row M. Each of the brackets 60 and 70 connects the lower module 1 and the upper module 2 of each of the three power storage modules 10 of the module row M. Each of the brackets 60 and 70 is fixed to the lower case 92 via a reinforcing member 81. That is, the module row M is fixed to the lower case 92 by each of the brackets 60 and 70.

[0038] The detailed structure of the reinforcing member 82 will be described with reference to Fig. 4 to Fig. 6. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 2. Fig. 5 is a cross-sectional view taken along line VV in Fig. 2. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 4.

[0039] 4 and 5, the power storage module 10a and the power storage module 10b are adjacent to each other in the horizontal direction (more specifically, in the Y direction). The power storage module 10b is disposed on the Y2 side of the power storage module 10a. The power storage module 10a is an example of a "first power storage module" in the present disclosure, and the power storage module 10b is an example of a "second power storage module" in the present disclosure.

[0040] The two-dot chain line R1 indicates the center position in the vertical direction of the energy storage module 10. That is, the two-dot chain line R1 indicates the center position in the vertical direction of the energy storage module 10a. The two-dot chain line R1 also indicates the center position in the vertical direction of the energy storage module 10b. The two-dot chain line R1 also indicates the center position in the vertical direction of the energy storage module 10c (see FIG. 1).

[0041] The smoke exhaust section 151a is a smoke exhaust section 151 that exhausts gas inside the lower module 1 of the power storage module 10a. The smoke exhaust section 151a is formed below the center of the power storage module 10a in the up-down direction. More specifically, the smoke exhaust section 151a is formed on the lower surface of the power storage module 10a. In this embodiment, the lower module 1 and the upper module 2 each include a plurality of power storage cells 13 arranged side by side in the X direction and a cell case 14 that houses the plurality of power storage cells 13. Each cell case 14 includes a bottom wall 14a and an top wall 14b that are arranged at an interval in the up-down direction (Z direction). The smoke exhaust section 151a is formed in the bottom wall 14a of the cell case 14 of the lower module 1 of the power storage module 10a.

[0042] The smoke exhaust section 152a is a smoke exhaust section 152 that exhausts gas inside the upper module 2 of the power storage module 10a. The smoke exhaust section 152a is formed above the center in the vertical direction of the power storage module 10a. More specifically, the smoke exhaust section 152a is formed on the upper surface of the power storage module 10a. In the present embodiment, the smoke exhaust section 152a is formed on the upper wall 14b of the cell casing 14 of the upper module 2 of the power storage module 10a.

[0043] The smoke exhaust section 151b is a smoke exhaust section 151 that exhausts gas inside the lower module 1 of the power storage module 10b. The smoke exhaust section 151b is formed below the center in the up-down direction of the power storage module 10b. More specifically, the smoke exhaust section 151b is formed on the underside of the power storage module 10b. In this embodiment, the smoke exhaust section 151b is formed on the bottom wall 14a of the cell casing 14 of the lower module 1 of the power storage module 10b.

[0044] The smoke exhaust section 152b is a smoke exhaust section 152 that exhausts gas inside the upper module 2 of the power storage module 10b. The smoke exhaust section 152b is formed above the center in the vertical direction of the power storage module 10b. More specifically, the smoke exhaust section 152b is formed on the upper surface of the power storage module 10b. In the present embodiment, the smoke exhaust section 152b is formed on the upper wall 14b of the cell casing 14 of the upper module 2 of the power storage module 10b.

[0045] The reinforcing member 82 is disposed between the power storage module 10a and the power storage module 10b. More specifically, the reinforcing member 82 passes between the power storage module 10a and the power storage module 10b and extends in the X direction along the bottom wall 921 of the lower case 92.

[0046] Of the two power storage modules 10 arranged with the reinforcing member 82 sandwiched between them, a first space Q1 is formed between the power storage module 10 arranged on the Y1 side and the reinforcing member 82. Of the two power storage modules 10 arranged with the reinforcing member 82 sandwiched between them, a second space Q2 is formed between the power storage module 10 arranged on the Y2 side and the reinforcing member 82. More specifically, the first space Q1 is formed between the power storage module 10a and the reinforcing member 82, and the second space Q2 is formed between the power storage module 10b and the reinforcing member 82.

[0047] The reinforcing member 82 includes a first wall portion 821, a second wall portion 822, an upper wall portion 823, and flange portions 824 and 825. The first wall portion 821 and the second wall portion 822 are arranged with an interval in the Y direction. The second wall portion 822 is arranged on the Y2 side of the first wall portion 821. The first wall portion 821 faces the power storage module 10 arranged on the Y1 side of the two power storage modules 10 arranged with the reinforcing member 82 in between. The second wall portion 822 faces the power storage module 10 arranged on the Y2 side of the two power storage modules 10 arranged with the reinforcing member 82 in between. More specifically, the first wall portion 821 faces the power storage module 10a, and the second wall portion 822 faces the power storage module 10b.

[0048] The upper wall portion 823 connects the upper ends of the first wall portion 821 and the second wall portion 822. The flange portion 824 is provided so as to protrude from the lower end of the first wall portion 821 toward the side of the energy storage module 10a that faces the first wall portion 821. More specifically, the flange portion 824 is provided so as to protrude from the lower end of the first wall portion 821 toward the side of the energy storage module 10a.

[0049] The flange portion 825 is provided so as to protrude from the lower end of the second wall portion 822 toward the side of the energy storage module 10b that faces the second wall portion 822. More specifically, the flange portion 825 is provided so as to protrude from the lower end of the second wall portion 822 toward the side of the energy storage module 10b.

[0050] The flange portions 824, 825 are fixed to the bottom wall 921 of the lower case 92. The flange portions 824, 825 may be fixed to the bottom wall 921 by fastening members, or may be fixed to the bottom wall 921 by welding or the like.

[0051] A hollow portion P1 is formed between the first wall portion 821 and the second wall portion 822. More specifically, the hollow portion P1 is formed by the first wall portion 821, the second wall portion 822, the upper wall portion 823, the flange portions 824 and 825, and the bottom wall 921 of the lower case 92.

[0052] The reinforcing member 82 is formed with a first hole 831 (see FIG. 4 ) and a second hole 832 (see FIG. 5 ) for allowing gas discharged from the smoke exhaust section 151 of one of the two power storage modules 10 arranged across the reinforcing member 82 to escape to an area where the other power storage module 10 is arranged. More specifically, as shown in FIG. 4 , the first hole 831 is formed in the first wall 821. The first hole 831 communicates between the first space Q1 and the hollow portion P1. As shown in FIG. 5 , the second hole 832 is formed in the second wall 822. The second hole 832 communicates between the second space Q2 and the hollow portion P1. In this embodiment, one first hole 831 is formed in the first wall 821, and one second hole 832 is formed in the second wall 822.

[0053] The two-dot chain line R2 indicates the vertical center position of the reinforcing member 82. The first hole portion 831 and the second hole portion 832 are each formed below the vertical center of the reinforcing member 82.

[0054] 6, the position of the first hole portion 831 and the position of the second hole portion 832 are offset in the extension direction of the reinforcing member 82. In this embodiment, the reinforcing member 82 extends in the X direction. Therefore, in this embodiment, the position of the first hole portion 831 and the position of the second hole portion 832 are offset in the X direction.

[0055] In Fig. 6, the flow of gas discharged from the power storage module 10a is indicated by dotted arrows. Part of the gas discharged from the smoke exhaust section 151a (see Fig. 4) of the power storage module 10a flows into the first space Q1. Part of the gas that has flowed into the first space Q1 flows into the hollow portion P1 through the first hole 831. The gas that has flowed into the hollow portion P1 flows into the second space Q2 through the second hole 832.

[0056] Furthermore, part of the gas discharged from the smoke exhaust section 151b (see FIG. 4) of the power storage module 10b flows into the second space Q2. Part of the gas that has flowed into the second space Q2 flows into the hollow section P1 through the second hole 832. The gas that has flowed into the hollow section P1 flows into the first space Q1 through the first hole 831.

[0057] Generally, when gas discharged from the power storage module 10 accumulates in the area where the power storage module 10 is placed, conductive foreign matter (debris) contained in the gas accumulates in the area, and the thermal effect of the conductive foreign matter causes thermal runaway of the power storage module 10. Thermal runaway of the power storage module 10 occurs when a chain reaction occurs in the multiple power storage cells 13 in the power storage module 10, causing them to become hot and emit smoke.

[0058] 4 to 6 , in the present embodiment, the first hole 831 and the second hole 832 are formed in the reinforcing member 82. This allows the gas discharged from the smoke exhaust section 151 of one of the two power storage modules 10 (for example, the power storage module 10a) disposed across the reinforcing member 82, and conductive foreign matter contained in the gas, to flow into the area where the other power storage module 10 (for example, the power storage module 10b) is disposed. That is, the gas discharged from the smoke exhaust section 151 of one of the two power storage modules 10 disposed across the reinforcing member 82, and conductive foreign matter contained in the gas, are prevented from accumulating in the area where the one power storage module 10 is disposed. This reduces the thermal effect on the one power storage module 10 of the conductive foreign matter contained in the gas discharged from the smoke exhaust section 151 of the one power storage module 10. Therefore, according to the power storage device 100 of this embodiment, thermal runaway of the power storage module 10 is suppressed.

[0059] As described above, in the energy storage device 100 of this embodiment, the first hole 831 is formed in the first wall 821 of the reinforcing member 82 disposed between the first energy storage module (for example, the energy storage module 10a) and the second energy storage module (for example, the energy storage module 10b), and the second hole 832 is formed in the second wall 822 of the reinforcing member 82. This prevents the gas discharged from the smoke exhaust section 151 of the first energy storage module and conductive foreign matter contained in the gas from accumulating in the area where the first energy storage module is disposed. This reduces the thermal influence that the first energy storage module receives from the conductive foreign matter contained in the gas discharged from the smoke exhaust section 151 of the first energy storage module. Therefore, the energy storage device 100 of this embodiment can prevent thermal runaway of the energy storage module 10.

[0060] Furthermore, according to the energy storage device 100 of this embodiment, thermal runaway of the first energy storage module is suppressed, which also suppresses an increase in internal pressure of the energy storage device 100. Therefore, according to the energy storage device 100 of this embodiment, it is possible to suppress rupture of the seal member connecting the upper case 91 and the lower case 92.

[0061] Furthermore, in the energy storage device 100 of this embodiment, the smoke exhaust section 151 of the first energy storage module (for example, the energy storage module 10a) is formed below the center in the up-down direction of the first energy storage module. Furthermore, in the energy storage device 100 of this embodiment, the first hole 831 and the second hole 832 are each formed below the center in the up-down direction of the reinforcing member 82. This allows the gas discharged from the smoke exhaust section 151 of the first energy storage module and conductive foreign matter contained in the gas to efficiently flow into the second space Q2 formed between the second energy storage module (for example, the energy storage module 10b) and the reinforcing member 82. This further reduces the thermal influence of conductive foreign matter contained in the gas discharged from the smoke exhaust section 151 of the first energy storage module on the first energy storage module. Therefore, the energy storage device 100 of this embodiment can further suppress thermal runaway of the energy storage module 10.

[0062] Furthermore, in the energy storage device 100 of this embodiment, the positions of the first hole 831 and the second hole 832 are offset in the extension direction of the reinforcing member 82. This prevents conductive foreign matter contained in the gas discharged from the smoke exhaust section 151 of the first energy storage module (e.g., the energy storage module 10a) from directly hitting the second energy storage module (e.g., the energy storage module 10b). Furthermore, because the positions of the first hole 831 and the second hole 832 are offset in the extension direction of the reinforcing member 82, the flow rate of the gas discharged from the smoke exhaust section 151 of the first energy storage module and the flow rate of conductive foreign matter contained in the gas are reduced. This reduces the thermal impact on the second energy storage module from conductive foreign matter contained in the gas discharged from the smoke exhaust section 151 of the first energy storage module. Therefore, the energy storage device 100 of this embodiment can prevent thermal runaway from occurring in a chain reaction between the first energy storage module and the second energy storage module.

[0063] [Variation 1] The number of first holes 831 formed in the first wall portion 821 is not limited to one. The number of first holes 831 formed in the first wall portion 821 may be one or more. The number of second holes 832 formed in the second wall portion 822 is not limited to one. The number of second holes 832 formed in the second wall portion 822 may be one or more.

[0064] [Variation 2] The position of the first hole 831 is not limited to the position shown in FIGS. 4 to 6. The first hole 831 may be formed at any position in the first wall 821. Furthermore, the position of the second hole 832 is not limited to the position shown in FIGS. 4 to 6. The second hole 832 may be formed at any position in the second wall 822. Therefore, each of the first hole 831 and the second hole 832 may be formed in the center of the reinforcing member 82 in the up-down direction or above the center of the reinforcing member 82 in the up-down direction. Furthermore, the positions of the first hole 831 and the second hole 832 do not need to be offset from each other in the extension direction of the reinforcing member 82.

[0065] [Variation 3] The reinforcing member 82 may not have the first hole portion 831 or the second hole portion 832, and the reinforcing member 81 (see Figure 1) may have a hole portion formed therein to allow gas discharged from the smoke exhaust section 151 of one of the two storage modules 10 arranged on either side of the reinforcing member 81 to escape to the area where the other storage module 10 is arranged.

[0066] Furthermore, the reinforcing member 82 may be formed with the first hole 831 and the second hole 832, and the reinforcing member 81 may be formed with holes for allowing gas discharged from the smoke exhaust section 151 of one of the two power storage modules 10 arranged across the reinforcing member 81 to escape to the area where the other power storage module 10 is arranged. This connects the nine areas inside the accommodating case 90, thereby improving the diffusion effect of conductive foreign matter contained in the gas discharged from the smoke exhaust section 151. This further suppresses thermal runaway of the power storage modules 10. [Variation 4] The smoke exhaust section 151 may be a cell smoke exhaust valve provided in the power storage cell 13. The smoke exhaust section 151 may also be a smoke exhaust port covered with a resin member or the like. When the smoke exhaust port is covered with a resin member or the like, the resin member is configured to break when exposed to high temperatures or high pressures.

[0067] The smoke exhaust section 152 may be a cell smoke exhaust valve provided in the power storage cell 13. The smoke exhaust section 152 may also be a smoke exhaust port covered with a resin member or the like. When the smoke exhaust port is covered with a resin member or the like, the resin member is configured to break when exposed to high temperatures or high pressures.

[0068] [Variation 5] The energy storage cell 13 may be a laminated cell. The laminated cell has a cell body and a laminated film that encases the cell body. The edges of the laminated film are welded together.

[0069] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. 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 lower module, 2 upper module, 10, 10a, 10b, 10c energy storage module, 13 energy storage cell, 14 cell case, 14a lower wall, 14b upper wall, 21 first bus bar, 22 second bus bar, 23 third bus bar, 30 cooler, 41, 42 cooling piping, 60, 70 bracket, 81, 82 reinforcing member, 90 storage case, 91 upper case, 92 lower case, 100 energy storage device, 110 energy storage unit, 151, 151a, 151b, 152, 152a, 152b smoke exhaust section, 821 first wall section, 822 second wall section, 823 upper wall section, 824, 825 flange section, 831 first hole section, 832 second hole section, 921 bottom wall, 922 Peripheral wall, 931, 932, 933, 934 side walls, M module row, P1 hollow section, Q1 first space, Q2 second space, R1, R2 two-dot chain lines.

Claims

1. a first power storage module; a second power storage module adjacent to the first power storage module; a reinforcing member disposed between the first power storage module and the second power storage module, a smoke exhaust section for exhausting gas from within the first power storage module is formed below the center in the up-down direction of the first power storage module, the reinforcing member includes a first wall portion facing the first power storage module and a second wall portion facing the second power storage module; a hollow portion is formed between the first wall portion and the second wall portion, a first space is formed between the first power storage module and the reinforcing member; a first hole portion that communicates the first space and the hollow portion is formed in the first wall portion; a second space is formed between the second power storage module and the reinforcing member, The second wall portion has a second hole portion formed therein, the second hole portion communicating with the second space and the hollow portion.

2. The power storage device according to claim 1 , wherein each of the first hole and the second hole is formed below a center of the reinforcing member in the up-down direction.

3. the power storage device further includes a housing case that includes an upper case and a lower case and that houses the first power storage module and the second power storage module; the reinforcing member passes between the first power storage module and the second power storage module and extends along the bottom wall of the lower case; The power storage device according to claim 1 , wherein the first hole and the second hole are positioned differently from each other in an extending direction of the reinforcing member.

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