Power storage device

Abstract

A power storage device (10) comprises: a first power storage cell (211) and a second power storage cell (221) that are aligned in a first direction with spacing therebetween; and a cross member (40) that extends along a second direction orthogonal to the first direction and is disposed in the gap between the first power storage cell (211) and the second power storage cell (221). The cross member (40) is provided with a hollow portion (H) in a cross section perpendicular to the second direction. The cross member (40) has: a first wall portion (41) that faces the first power storage cell (211) in the first direction; and a partition wall (45) that intersects the first direction in the cross section and partitions the hollow portion (H). At least a part of the partition wall (45) is provided with a region having a higher reflectance than that of the first wall portion (41).

Description

Power storage device

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

[0002] A conventional energy storage device disclosed in JP 2023-165300 A (Patent Document 1) includes a cross member that divides the space inside a battery case into multiple regions, and an energy storage module is disposed in each of the multiple regions.

[0003] JP 2023-165300 A

[0004] Generally, an electric storage module includes a plurality of electric storage cells, and when one electric storage cell generates heat, the radiant heat may be transferred to the other electric storage cells.

[0005] In the energy storage device described in Patent Document 1, a cross member is disposed between adjacent energy storage modules. However, if the cross member is not provided with any special measures, most of the radiant heat from the energy storage cells included in one of the adjacent energy storage modules passes through the cross member. In this case, the radiant heat may cause a temperature rise in the energy storage cells included in the other of the adjacent energy storage modules.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and an object of the present disclosure is to provide a storage device that can reduce the effect of radiant heat from one storage cell to the other storage cell in a configuration in which a first storage cell and a second storage cell are arranged so that a cross member is located between them.

[0007] An energy storage device according to the present disclosure includes first and second storage cells arranged side by side at a distance in a first direction, and a cross member extending along a second direction perpendicular to the first direction and arranged between the first and second storage cells. The cross member has a hollow portion in a cross section perpendicular to the second direction. The cross member has a first wall portion facing the first storage cell in the first direction, and a partition wall that intersects the first direction in the cross section and separates the hollow portion. At least a portion of the partition wall has an area with a higher reflectivity than the first wall portion.

[0008] According to the above configuration, the hollow portion of the cross member is partitioned by a partition wall that intersects with the first direction in which the first and second storage cells are arranged. The partition wall can suppress transmission of radiant heat from one of the first and second storage cells toward the other storage cell. This reduces the influence of radiant heat from the one storage cell to the other storage cell. Furthermore, by providing a region with high reflectivity in at least a portion of the partition wall, transmission of radiant heat from one of the first and second storage cells toward the other storage cell can be further suppressed.

[0009] In the power storage device according to the present disclosure, the partition wall may have a thickness equal to or smaller than a thickness of the first wall portion.

[0010] Also with the above configuration, the partition wall is provided, so that it is possible to suppress transmission of radiant heat from one of the first and second storage cells to the other storage cell.

[0011] In the power storage device based on the present disclosure, the partition wall may have a projected area in the first direction that is 25% or more and 100% or less of a projected area of ​​the first wall portion in the first direction.

[0012] According to the above configuration, by setting the projected area of ​​the partition wall as described above, it is possible to suppress an increase in the weight of the cross member while reducing the effect of radiant heat from one storage cell to the other storage cell.

[0013] In the energy storage device based on the present disclosure, the smaller of the intersection angles at which the first direction and the partition wall intersect may be greater than or equal to 45 degrees and less than 90 degrees, or the intersection angle may be 90 degrees.

[0014] When the crossing angle is set as described above, radiant heat from one of the first and second storage cells toward the other storage cell can be effectively reflected toward the side where the one storage cell is located, thereby reducing the influence of radiant heat from one storage cell on the other storage cell.

[0015] In the power storage device according to the present disclosure, the first power storage cell may have a first exhaust valve, and the first exhaust valve may face the cross member in the first direction.

[0016] According to the above configuration, by first discharging the exhaust from the first exhaust valve toward the cross member, it is possible to prevent the exhaust from scattering while still in a high temperature state.

[0017] In the power storage device according to the present disclosure, the second power storage cell may have a second exhaust valve, and the second exhaust valve may face the cross member in the first direction.

[0018] According to the above configuration, by first discharging the exhaust from the second exhaust valve toward the cross member, it is possible to prevent the exhaust from scattering while still in a high temperature state.

[0019] In the power storage device according to the present disclosure, the first exhaust valve may be arranged to overlap the partition wall when viewed from the first direction.

[0020] According to the above configuration, the first exhaust valve and the partition wall overlap in the first direction, thereby preventing radiant heat from being transmitted from the second storage cell to the first exhaust valve, which is relatively vulnerable to heat compared to other components that make up the first storage cell.

[0021] In the power storage device according to the present disclosure, the first wall portion may be provided with a first opening at a position opposite the first exhaust valve.

[0022] According to the above configuration, when exhaust is discharged from the first exhaust valve, the exhaust can be introduced into the inside of the cross member through the first opening, thereby allowing the exhaust to remain inside the cross member and preventing the exhaust from scattering.

[0023] In the power storage device according to the present disclosure, the first opening may be covered with a breakable heat insulating member.

[0024] According to the above configuration, when waste is discharged from the first exhaust valve of the first energy storage cell, the momentum of the discharged waste breaks the insulating member. This allows the waste to be introduced into the cross member through the first opening. This allows the waste to be retained inside the cross member and prevents the waste from scattering. On the other hand, when waste is discharged from the second energy storage cell, the insulating member can prevent heat from flowing from the first opening toward the first energy storage cell, thereby preventing a temperature rise in the first energy storage cell.

[0025] In the power storage device according to the present disclosure, the heat insulating member may have an easily breakable portion.

[0026] According to the above configuration, when exhaust is discharged from the first exhaust valve of the first energy storage cell, the heat insulating member can be easily broken.

[0027] In the power storage device according to the present disclosure, the easily breakable portion may be formed by a break line, and in this case, the first exhaust valve may be disposed opposite the break line in the first direction.

[0028] According to the above configuration, when exhaust is discharged from the first exhaust valve of the first energy storage cell, the heat insulating member can be more reliably broken.

[0029] In the power storage device according to the present disclosure, the cross member may be provided with a communication portion that communicates the hollow portion with a space surrounding the cross member, and the communication portion may be provided at a position that does not face the first exhaust valve.

[0030] According to the above configuration, by discharging the gas contained in the exhaust introduced into the inside of the cross member from the first opening through the communicating portion, it is possible to prevent the internal pressure of the cross member from increasing excessively due to the gas introduced into the inside of the cross member from the first opening.

[0031] The power storage device according to the present disclosure may further include a bottom surface defining portion that defines a bottom surface of the hollow portion. An end of the partition wall that is located on the bottom surface defining portion side may be a free end, and a gap may be provided between the free end and the bottom surface defining portion.

[0032] According to the above configuration, the exhaust from the exhaust valve that is introduced into the inside of the cross member through the first opening can be stored in the gap. In addition, a sufficient amount of the exhaust can be stored, and the exhaust can be prevented from scattering into the space around the first energy storage cell.

[0033] In the power storage device according to the present disclosure, the communication portion may be provided above the first exhaust valve in a vertical direction perpendicular to the first direction and the second direction.

[0034] According to the above configuration, when gas contained in the exhaust introduced into the inside of the cross member from the first opening is discharged from the communication portion, it can be discharged above the first exhaust valve.

[0035] In the energy storage device according to the present disclosure, a height of the cross member in the vertical direction may be greater than a height of the first energy storage cell and the second energy storage cell in the vertical direction. The communication portion may be provided above the first energy storage cell and the second energy storage cell.

[0036] According to the above configuration, when gas contained in the discharged material introduced into the cross member from the first opening is discharged from the communication portion, it can be discharged above the first and second energy storage cells, thereby making it possible to prevent the gas from the communication portion from blowing against the first and second energy storage cells and to prevent a temperature rise in the first and second energy storage cells due to the gas blown out from the communication portion.

[0037] In the power storage device according to the present disclosure, the cross member may have an upper wall portion in the vertical direction, and the communication portion may be provided in the upper wall portion.

[0038] According to the above configuration, when gas contained in the exhaust introduced into the cross member from the first opening is discharged from the communication portion, the gas is discharged upward from the upper wall portion, which makes it possible to prevent the gas from the communication portion from blowing against the first and second energy storage cells and to prevent a temperature increase in the first and second energy storage cells due to the gas blown out from the communication portion.

[0039] In the power storage device according to the present disclosure, the partition wall may have a plurality of wall portions arranged at intervals in the first direction.

[0040] According to the above configuration, the partition wall includes a plurality of wall portions, which can further suppress transmission of radiant heat from one of the first and second storage cells to the other storage cell.

[0041] The energy storage device based on the present disclosure may further include a third energy storage cell arranged on the opposite side of the first energy storage cell from the side on which the second energy storage cell is located in the first direction, and a cooler arranged in the gap between the first energy storage cell and the third energy storage cell, which cools the first energy storage cell and the third energy storage cell.

[0042] According to the above configuration, even if heat is transferred from the second storage cell to the first storage cell, the first storage cell can be cooled by the cooler, and the cooler arranged between the first storage cell and the third storage cell can prevent the heat from being transferred to the third storage cell.

[0043] According to the present disclosure, it is possible to provide a storage device in which a first storage cell and a second storage cell are arranged so that a cross member is positioned between them, and which can reduce the effect of radiant heat from one storage cell to the other storage cell.

[0044] 8 is a schematic diagram of a vehicle including an electricity storage device according to Embodiment 1. FIG. 9 is a diagram showing a state in which the electricity storage device according to Embodiment 1 is fixed to a vehicle. FIG. 10 is a plan view showing the interior of the electricity storage device according to Embodiment 1. FIG. 11 is a cross-sectional view taken along line IV-IV shown in FIG. 3. FIG. 12 is a cross-sectional view showing a cross member and its peripheral structure according to a first modified example. FIG. 13 is a cross-sectional view showing a cross member and its peripheral structure according to a second modified example. FIG. 14 is an exploded perspective view of an electricity storage device according to Embodiment 2. FIG. 15 is a cross-sectional view taken along line IX-IX shown in FIG. 16. FIG. 17 is a plan view of a heat insulating member covering an opening of a cross member in an electricity storage device according to Embodiment 2. FIG. 18 is a schematic cross-sectional view showing movement of waste discharged from a second electricity storage cell in an electricity storage device according to Embodiment 2. FIG. 19 is a cross-sectional view showing a cross member and its peripheral structure according to a third modified example. FIG. 19 is a cross-sectional view showing a cross member and its peripheral structure according to a fourth modified example. FIG. 19 is a cross-sectional view showing a cross member and its peripheral structure according to a fifth modified example. FIG. 19 is an exploded perspective view of an electricity storage device according to Embodiment 3. FIG. 19 is a cross-sectional view showing the interior of an electricity storage device according to Embodiment 4.

[0045] Hereinafter, embodiments and modifications of the present disclosure will be described in detail with reference to the drawings. In the embodiments and modifications described below, the same or common parts are denoted by the same reference numerals in the drawings, and their description will not be repeated.

[0046] In the embodiments and variations described below, when numbers, amounts, etc. are mentioned, the scope of the present disclosure is not necessarily limited to those numbers, amounts, etc., unless otherwise specified. Furthermore, in the embodiments and variations described below, each component is not necessarily essential to the present disclosure, unless otherwise specified. Furthermore, when multiple embodiments and variations are described below, it is intended from the beginning that the characteristic portions of each embodiment and variation may be appropriately combined, unless otherwise specified.

[0047] (First Embodiment) Fig. 1 is a schematic diagram of a vehicle equipped with an electricity storage device according to the first embodiment. Fig. 2 is a diagram showing how the electricity storage device according to the first embodiment is fixed to the vehicle. Vehicle 1 according to the first embodiment will be described with reference to Figs. 1 and 2 .

[0048] The vehicle 1 is a hybrid vehicle that can run using the power of at least one of a motor and an engine, or an electric vehicle that runs using driving force obtained from electrical energy.

[0049] The vehicle 1 includes a vehicle body 2, front wheels 3, rear wheels 4, and an electricity storage device 10. The vehicle body 2 includes a frame member 5. The electricity storage device 10 is disposed below the vehicle body 2. The electricity storage device 10 is disposed, for example, between the front wheels 3 and the rear wheels 4. Note that a portion of the electricity storage device 10 may be disposed overlapping the front wheels 3 and / or the rear wheels 4 when viewed in the width direction of the vehicle 1. The electricity storage device 10 has an upper surface 10a. The upper surface 10a may function as a floor member that defines the interior of the vehicle cabin.

[0050] The framework member 5 includes a pair of side members 6 and a pair of side sills 7. The pair of side sills 7 are arranged on both ends of the vehicle 1 in the width direction. The pair of side members 6 are arranged at a distance inside the pair of side sills 7. The pair of side members 6 and the pair of side sills 7 extend along the front-rear direction of the vehicle 1.

[0051] The pair of side members 6 are spaced apart in the width direction of the vehicle 1. A main body 35 of the energy storage device 10 is disposed in the gap between the pair of side members 6. A gap is provided between the main body 35 and the pair of side members 6. This makes it possible to suppress input of an impact to the energy storage device 10 even in the event of a side collision of the vehicle 1.

[0052] Fixed portions 36 are provided on both side surfaces of the main body portion 35 in the width direction of the vehicle 1. The fixed portions 36 are fixed to the pair of side members 6 by fastening members 8.

[0053] The framework member 5 also includes a cross framework member 9. The cross framework member 9 is provided above the power storage device 10 so as to straddle from one side sill 7 to the other side sill 7. An upper surface 10a of the power storage device 10 is fixed to the cross framework member 9.

[0054] In the above description, the framework member 5 includes a pair of side members 6 and a pair of side sills 7, but is not limited to this. The pair of side sills 7 may also function as the pair of side members 6. In this case, the pair of side members 6 can be omitted, and the above-described fixed portion 36 may be fixed to the pair of side sills 7.

[0055] 3 is a plan view showing the inside of the power storage device according to Embodiment 1. With reference to FIG. 3, the power storage device 10 will be described in detail.

[0056] As shown in FIG. 3 , the energy storage device 10 includes a plurality of energy storage modules 20 , a housing case 30 , a plurality of cross members 40 , and electronic equipment 95 .

[0057] The plurality of power storage modules 20 include a first power storage stack 21 and a second power storage stack 22. The first power storage stack 21 and the second power storage stack 22 are arranged at an interval in a first direction (DR1 direction). In the present embodiment, the first direction is, for example, parallel to the front-rear direction of the vehicle 1 when the power storage device 10 is mounted on the vehicle body 2.

[0058] The first power storage stack 21 includes a plurality of first power storage cells 211. The plurality of first power storage cells 211 are arranged in a second direction (DR2 direction) that is perpendicular to the first direction. In the present embodiment, the second direction is, for example, parallel to the width direction of the vehicle 1 in the mounted state. The second power storage stack 22 includes a plurality of second power storage cells 221. The plurality of second power storage cells 221 are arranged side by side in the second direction.

[0059] The first storage cell 211 and the second storage cell 221 have an elongated shape with the longitudinal direction being the first direction. The first storage cell 211 and the second storage cell 221 have a flat rectangular parallelepiped shape with a thickness in the second direction.

[0060] The first storage cell 211 and the second storage cell 221 may be configured as the same storage cell. In this case, the number of components can be reduced, and manufacturing costs can be reduced. Note that "same" includes manufacturing errors such as tolerances. Alternatively, the first storage cell 211 and the second storage cell 221 may be configured as different storage cells.

[0061] The first storage cell 211 includes a housing 212 (see FIG. 4 ), and the second storage cell 221 includes a housing 222 (see FIG. 4 ). One or more electrode bodies 25 are housed inside each of the housings 212, 222. The housing 212 has a pair of side walls 214, 213 arranged in a first direction. The side wall 214 is located on one side in the first direction, and the side wall 213 is located on the other side in the first direction. The housing 222 has a pair of side walls 223, 224 arranged in the first direction. The side wall 223 is located on one side in the first direction, and the side wall 224 is located on the other side in the first direction.

[0062] When a single electrode body 25 is housed in the housing 212, 222, the electrode body has a shape extending in the longitudinal direction. The electrode body 25 may be a laminated electrode body in which a negative electrode sheet, a separator, and a positive electrode sheet are laminated, or may be a wound electrode body in which a negative electrode sheet, a separator, and a positive electrode sheet are wound.

[0063] When multiple electrode bodies are housed in the housings 212 and 222, the multiple electrode bodies are arranged side by side in the longitudinal direction and connected in series. In this case, too, the electrode body may be a stacked electrode body or a wound electrode body.

[0064] The first storage cell 211 and the second storage cell 221 are secondary batteries such as nickel-metal hydride batteries or lithium-ion batteries. The first storage cell 211 and the second storage cell 221 may use a liquid electrolyte or a solid electrolyte. The first storage cell 211 and the second storage cell 221 may be chargeable and dischargeable capacitors.

[0065] The storage case 30 includes an upper member 31 (see FIG. 4) and a lower member 32. The lower member 32 has a generally box-like shape that opens upward. The lower member 32 includes a main body 35 and a fixed portion 36. The main body 35 has a bottom wall 321, a front wall 322, a rear wall 323, and side walls 324 and 325. The front wall 322, the rear wall 323, and the side walls 324 and 325 are provided to stand upright from the periphery of the bottom wall 321.

[0066] The front wall 322 and the rear wall 323 face each other in a first direction. The side walls 324 and 325 face each other in a second direction. The fixed portions 36 are provided on the outer surfaces of the side walls 324 and 325.

[0067] The multiple cross members 40 are provided to divide the storage space within the storage case 30. Specifically, the cross members 40 are provided to extend in the second direction. In this embodiment, the two cross members 40 divide the storage space within the storage case 30 into three sections in the first direction.

[0068] In each of the three divided regions, an electronic device 95, a first power storage stack 21, and a second power storage stack 22 are arranged in this order from one side in the first direction. A cross member 40 is arranged in the gap between the electronic device 95 and the first power storage stack 21, and a cross member 40 is arranged in the gap between the first power storage stack 21 and the second power storage stack 22.

[0069] The number of cross members 40 is not limited to two, and may be one, or three or more, as long as they are disposed in the gap between the adjacent first power storage stack 21 and second power storage stack 22. The cross member 40 is made of a metal member such as SUS. Furthermore, the cross member 40 may be made of a high-tensile material. By making the cross member 40 of a high-tensile material, the rigidity of the power storage device 10 can be improved.

[0070] Of the multiple cross members 40, at least the cross member arranged in the gap between the first power storage stack 21 and the second power storage stack 22 has a hollow portion H (see FIG. 4 ). Note that all of the multiple cross members 40 may have a hollow portion H. The hollow portion H may form part of an exhaust path for gas that is discharged when heat is generated by any of the power storage cells included in the first power storage stack 21 and the second power storage stack 22.

[0071] The upper member 31 covers the plurality of power storage modules 20 and closes the open space of the lower member 32. A sealing member may be filled in the gap between the upper member 31 and the power storage modules 20. The sealing member may have insulating properties. The upper member 31 has, for example, a substantially flat plate shape. Note that the upper member 31 is not limited to a flat plate shape and may have a substantially box-like shape that opens downward.

[0072] The electronic device 95 controls the plurality of power storage modules 20. The electronic device 95 is, for example, a battery ECU.

[0073] Figure 4 is a cross-sectional view taken along line IV-IV in Figure 3, and more specifically shows the cross member and its surrounding structure. For convenience, Figure 4 also shows the upper member of the storage case 30. Details of the cross member 40 and its surrounding structure will be described with reference to Figure 4.

[0074] As described above, the cross member 40 has a hollow portion H in a cross section perpendicular to the second direction. The hollow portion H is provided so as to extend continuously in the second direction. The cross member 40 includes a first wall portion 41, a second wall portion 42, an upper wall portion 43, a bottom wall portion 44, and a partition wall 45.

[0075] The first wall portion 41 is located on one side in the first direction. The first wall portion 41 faces the first storage cell 211 in the first direction. The second wall portion 42 is located on the other side in the first direction. The second wall portion 42 faces the second storage cell 221 in the first direction. The heights of the first wall portion 41 and the second wall portion 42 in the vertical direction (up and down direction) are higher than the heights of the first storage cell 211 and the second storage cell 221. The vertical direction is a direction perpendicular to the first direction and the second direction.

[0076] The height of the first wall portion 41 and the second wall portion 42 may be the same as the height of the first storage cell 211 and the second storage cell 221 .

[0077] The upper wall portion 43 and the bottom wall portion 44 face each other in the vertical direction. The upper wall portion 43 connects the upper ends of the first wall portion 41 and the second wall portion 42. The bottom wall portion 44 connects the lower ends of the first wall portion 41 and the second wall portion 42. The bottom wall portion 44 functions as a bottom surface defining portion that defines the bottom surface of the hollow portion H. The bottom wall portion 44 is fixed to the bottom wall portion 321 of the storage case 30.

[0078] The partition wall 45 is disposed between the first wall portion 41 and the second wall portion 42. The partition wall 45 is provided so as to intersect with the first direction. More specifically, the partition wall 45 is perpendicular to the first direction. The partition wall 45 separates the hollow portion H. The partition wall 45 extends in the second direction. When viewed from the first direction, the partition wall 45 is provided so as to overlap with the first power storage stack 21 and the second power storage stack 22 across the second direction. The partition wall 45 may be provided so as to extend from one end of the cross member 40 in the second direction to the other end of the cross member 40 in the second direction.

[0079] In the present embodiment, partition wall 45 is provided to connect upper wall portion 43 and bottom wall portion 44, but the height of partition wall 45 is not limited to this. As will be described later, the height of partition wall 45 can be set as appropriate as long as it is possible to suppress the transmission of radiant heat from one of first storage cell 211 and second storage cell 221 to the other storage cell.

[0080] The thickness T1 of the partition wall 45 is equal to or smaller than the thickness T2 of the first wall portion 41. The thickness direction is the normal direction to the widest surface of the partition wall 45. In this embodiment, the thickness direction is parallel to the first direction. The thickness T2 of the first wall portion 41 may be the same as or different from the thickness of the second wall portion 42.

[0081] The housing 212 of the first storage cell 211 has a side wall portion 213 that faces the first wall portion 41 in the first direction. The side wall portion 213 is provided with an external terminal 213A and a first exhaust valve 216.

[0082] The first exhaust valve 216 is a valve for discharging exhaust materials from inside the first storage cell 211. The exhaust materials include gases. The exhaust materials may also include foreign matter such as electrolytes and metallic foreign matter. The first exhaust valve 216 functions as a pressure release valve. The first exhaust valve 216 is configured to rupture when the internal pressure of the housing 212 reaches or exceeds a predetermined level. The first exhaust valve 216 is provided, for example, in the center of the side wall portion 213 in the vertical direction.

[0083] The first exhaust valve 216 faces the cross member 40 (more specifically, the first wall portion 41) in the first direction. The first exhaust valve 216 is disposed so as to overlap the partition wall 45 when viewed from the first direction.

[0084] The external terminal 213A is disposed, for example, above the first exhaust valve 216. The external terminal 213A faces the first wall portion 41 in the first direction.

[0085] The housing 222 of the second storage cell 221 has a side wall 223 that faces the second wall 42 in the first direction. An external terminal 223A and a second exhaust valve 226 are provided on the side wall 223. The side wall 223 is arranged to face the side wall 213 in the first direction. A cross member 40 is located between the side wall 223 and the side wall 213.

[0086] The second exhaust valve 226 is a valve for discharging the above-mentioned exhaust from inside the second energy storage cell 221. The second exhaust valve 226 functions as a pressure release valve. The second exhaust valve 226 is provided so as to rupture when the internal pressure of the housing 222 reaches or exceeds a predetermined level. The second exhaust valve 226 is provided, for example, in the center of the side wall portion 223 in the vertical direction.

[0087] The second exhaust valve 226 faces the cross member 40 (more specifically, the second wall portion 42) in the first direction. The second exhaust valve 226 is disposed so as to overlap the partition wall 45 when viewed from the first direction.

[0088] The external terminal 223A is disposed, for example, above the second exhaust valve 226. The external terminal 223A faces the second wall portion 42 in the first direction.

[0089] When a storage cell included in the plurality of power storage modules 20 generates heat, that is, when one of the first storage cell 211 and the second storage cell 221 generates heat, the exhaust valve (specifically, the first exhaust valve 216 or the second exhaust valve 226) provided on the one storage cell breaks, and exhaust including high-temperature gas is discharged into the accommodation case 30. In this state, the temperature of the one storage cell has risen to a considerable degree, and radiant heat is released from the one storage cell toward the other of the first storage cell 211 and the second storage cell 221.

[0090] In the present embodiment, the hollow portion H of the cross member 40 is partitioned by a partition wall 45 that intersects with the first direction in which the first storage cells 211 and the second storage cells 221 are arranged. The partition wall 45 can suppress the transmission of radiant heat from one storage cell to the other storage cell. Specifically, for example, when the reflectance of the partition wall 45 is set to 0.5, the heat flux from the one storage cell to the other storage cell can be reduced to one-sixth compared to a configuration in which the partition wall 45 is not provided. In this way, the influence of radiant heat from the one storage cell to the other storage cell can be reduced.

[0091] Furthermore, by making the thickness T1 of the partition wall 45 equal to or less than the thickness T2 of the first wall portion 41, it is possible to suppress an increase in the weight of the cross member 40, and in turn, to suppress an increase in the weight of the energy storage device 10. The relationship between the thicknesses T1 and T2 as described above is suitable in an environment where it is required to suppress an increase in weight from the viewpoint of fuel efficiency, etc.

[0092] Furthermore, as described above, the first exhaust valve 216 and the second exhaust valve 226 are disposed to face the cross member 40. This allows the exhaust, when discharged from the first exhaust valve 216 or the second exhaust valve 226, to be discharged first toward the cross member 40. This makes it possible to prevent the discharged material from scattering while still in a high temperature state. At this time, since the external terminals 213A and 223A are positioned above the first exhaust valve 216 and the second exhaust valve 226, it is possible to prevent the discharged material from adhering to the external terminals 213A and 223A.

[0093] In addition, as described above, by overlapping the first exhaust valve 216 and the second exhaust valve 226 with the partition wall 45 in the first direction, when exhaust is discharged from one of the storage cells, it is possible to prevent radiant heat from being transmitted to the first exhaust valve 216 or the second exhaust valve 226, which are vulnerable to heat.

[0094] Furthermore, at least a portion of the partition wall 45 may be provided with an area having a higher reflectivity than the first wall portion 41. The area may be surface-treated, and may be provided with, for example, a reflective film. The reflective film may be made of a resin material or a metal material such as aluminum. In such a case, it is possible to further suppress the transmission of radiant heat from the one power storage cell to the other power storage cell.

[0095] In the first embodiment described above, the case where the first exhaust valve 216 is provided on the side wall 213 of the housing 212 facing the second storage cell 221 has been described as an example, but the present invention is not limited to this. The first exhaust valve 216 may be provided on the side wall 214 of the housing 212. The side wall 214 faces the side opposite to the side on which the second storage cell 221 is located. More specifically, the side wall 214 faces the side on which the electronic device 95 is located.

[0096] In this case, the cross member 40 described above is disposed between the electronic device 95 and the first storage cell 221 (more specifically, the first storage stack 21), and when the first storage cell 221 generates heat, it is possible to suppress the radiant heat from the first storage cell 221 from being transmitted to the electronic device 95. This makes it possible to suppress a temperature rise in the electronic device 95.

[0097] Furthermore, by having the first exhaust valve 216 face the cross member 40 arranged between the first power storage stack 21 and the electronic device 95 in the first direction, the exhaust material discharged from the first exhaust valve can be discharged first toward the cross member 40, thereby preventing the exhaust material from scattering while still in a high temperature state. Note that in the above case, the second exhaust valve 216 may be provided on the side wall portion 223 or the side wall portion 224.

[0098] 5 is a cross-sectional view showing a cross member and its surrounding structure according to a first modification. In a power storage device 10A according to the first modification, the shape of a cross member 40A is changed compared to that of the first embodiment. The other configurations are substantially the same.

[0099] In the cross member 40A according to the first modification, the partition wall 45 intersects with the first direction (DR1 direction). The smaller of the intersection angles θ between the first direction and the partition wall 45 is equal to or greater than 45 degrees and less than 90 degrees. In the first embodiment, the intersection angle θ is 90 degrees.

[0100] By setting the crossing angle as described above, it is possible to effectively reflect radiant heat from the one energy storage cell toward the other energy storage cell toward the side where the one energy storage cell is located. More specifically, it is possible to reflect radiant heat parallel to the first direction so as not to include a component directed toward the other energy storage cell. As a result, even in the first modification, it is possible to reduce the influence of radiant heat from the one energy storage cell to the other energy storage cell.

[0101] In addition, within the above range of the intersection angle θ, when the intersection angle θ is large (for example, when the intersection angle θ is greater than or equal to 60 degrees and less than or equal to 90 degrees), the area of ​​the partition wall 45 becomes wider, thereby further reducing the effects of radiant heat.

[0102] Furthermore, within the above range of the intersection angle θ, when the value of the intersection angle θ is small (for example, when the intersection angle θ is equal to or greater than 45 degrees and less than 60 degrees), the area of ​​the partition wall 45 can be made smaller, thereby further suppressing the increase in weight and further reducing the influence of radiant heat.

[0103] In the above description, an example is given in which the partition wall 45 slopes upward as it approaches the second wall portion 42, but this is not limited to this, and the partition wall 45 may also slope downward as it approaches the second wall portion 42.

[0104] 6 is a cross-sectional view showing a cross member and its surrounding structure according to a second modification. Note that a power storage device 10B according to the second modification has a cross member 40B with a different projected area compared to the first embodiment. The other configurations are substantially the same.

[0105] The cross member 40B according to the second modification has a different ratio of the projected area S1 of the partition wall 45 in the first direction to the projected area S2 of the first wall portion 41 in the first direction. Note that, although the second modification illustrates an example in which the partition wall 45 intersects with the first wall portion 41, the partition wall 45 may be parallel to the first wall portion 41.

[0106] In the first embodiment, the projection area S1 is 100% of the projection area S2, but in the second modification, the projection area S1 is 25% or more and less than 100% of the projection area S2.

[0107] When the configuration of the second modified example is combined with the configuration of the first embodiment, the projection area S1 may be 25% to 100% of the projection area S2. Alternatively, the projection area S1 may be 50% to 100% of the projection area S2. Furthermore, the projection area S1 may be 75% to 100% of the projection area S2.

[0108] When the projected area S1 is less than 25% of the projected area S2, the proportion of radiant heat traveling from one energy storage cell to the other energy storage cell that passes through the cross member increases, but when the projected area S1 is 25% or more of the projected area S2, the transmission of the radiant heat can be significantly suppressed by the partition wall 45. When the projected area S1 is 50% or more of the projected area S2, the transmission of the radiant heat can be effectively suppressed by the partition wall 45. When the projected area S1 is 75% or more of the projected area S2, the transmission of the radiant heat can be more reliably suppressed by the partition wall 45.

[0109] In the above, when the projection area S1 is small, by arranging the partition wall 45 so that it overlaps with the first exhaust valve 216 and the second exhaust valve 226 in the first direction, even if the partition wall 45 is small, the effect of radiant heat from one storage cell to the other storage cell can be effectively reduced.

[0110] Second Embodiment Fig. 7 is an exploded perspective view of a power storage device according to a second embodiment. A power storage device 10C according to the second embodiment will be described with reference to Fig. 7 .

[0111] The energy storage device 10C according to the second embodiment differs from the energy storage device 10 according to the first embodiment mainly in the arrangement and structure of the plurality of energy storage modules 20 and the cross members 40, and in the inclusion of a partition wall 50. The other configurations are substantially the same.

[0112] In the second embodiment, when the power storage device 10C is mounted on the vehicle body 2, the first direction is parallel to the width direction of the vehicle 1, and the second direction is parallel to the front-rear direction of the vehicle 1.

[0113] The plurality of power storage modules 20 are arranged in a matrix in the first direction and the second direction. Within the accommodating case 30, the areas in which the power storage modules 20 are arranged are partitioned by a plurality of cross members 40 and a plurality of partition walls 50.

[0114] The cross members 40 are arranged side by side at intervals in the first direction. The cross members 40 are arranged in the gaps between the power storage modules 20 adjacent to each other in the first direction. The cross members 40 extend in the second direction. The cross members 40 extend from the front wall portion 322 toward the rear wall portion 323 of the lower member 32 of the accommodating case 30.

[0115] The partition walls 50 partition the space within the accommodating case 30, which is partitioned by the cross members 40, into sections corresponding to the number of the plurality of power storage modules 20. The partition walls 50 extend in the first direction. The partition walls 50 may have a hollow structure.

[0116] An exhaust unit 80 is provided on the upper member 31 of the storage case 30. The exhaust unit 80 exhausts gas inside the storage case 30 when the internal pressure inside the storage case 30 exceeds a predetermined pressure. Specifically, when gas is exhausted into the storage case 30 from the power storage cells included in the plurality of power storage modules 20 and the internal pressure inside the storage case 30 exceeds a predetermined pressure, the exhaust unit 80 exhausts the gas to the outside of the storage case 30.

[0117] In addition, when the exhaust section 80 is provided in the upper member 31 as in this embodiment, the vehicle 1 is structured so that gas exhausted from the exhaust section 80 is not introduced into the interior of the vehicle 1.

[0118] Fig. 8 is a plan view showing the inside of the energy storage device according to embodiment 2. As shown in Fig. 8 , of the energy storage modules 20 adjacent to each other in the first direction, the energy storage module 20 located on one side in the first direction includes a first energy storage stack 21 and a third energy storage stack 23. Of the energy storage modules 20 adjacent to each other in the first direction, the energy storage module 20 located on the other side in the first direction includes a second energy storage stack 22 and a fourth energy storage stack 24.

[0119] In the energy storage module 20 located on one side in the first direction, the first energy storage stack 21 and the third energy storage stack 23 are arranged to face each other in the first direction.

[0120] The first power storage stack 21 has a plurality of first power storage cells 211. The plurality of first power storage cells 211 are arranged in the second direction. The first power storage cell 211 has a pair of side wall portions in the first direction, and external terminals 213A and 213B (see FIG. 9 ) that are curved differently from each other are provided on a side wall portion 213 (see FIG. 9 ) that is located on the side closest to the cross member 40C. Of the pair of side wall portions, the side wall portion located opposite the side wall portion 213 is in thermal contact with a cooler 70, which will be described later.

[0121] The third power storage stack 23 is arranged on the opposite side of the first power storage stack 21 from the side on which the second power storage stack 22 is located. The third power storage stack 23 has a plurality of third power storage cells 231. The plurality of third power storage cells 231 are arranged in the second direction. The third power storage cells 231 are arranged on the opposite side of the first power storage cells 211 from the side on which the second power storage cells 221 included in the second power storage stack 22 are located. The third power storage cells 231 include a sidewall portion on the side opposite to the side on which the first power storage cells 211 are located, and external terminals of mutually opposite polarities are provided on the sidewall portion.

[0122] In the energy storage module 20 located on the other side in the first direction, the second energy storage stack 22 and the fourth energy storage stack 24 are arranged to face each other in the first direction.

[0123] The second power storage stack 22 has a plurality of second power storage cells 221. The plurality of second power storage cells 221 are arranged in the second direction. The second power storage cell 221 has a pair of side wall portions in the first direction, and external terminals 223A and 223B (see FIG. 9 ) that are curved differently from each other are provided on the side wall portion 223 (see FIG. 9 ) that is located on the side closest to the cross member 40C. Of the pair of side wall portions, the side wall portion located opposite the side wall portion 223 is in thermal contact with the cooler 70, which will be described later.

[0124] The fourth power storage stack 24 is arranged with respect to the second power storage stack 22 on the opposite side to the side on which the above-mentioned first power storage stack 21 is located. The fourth power storage stack 24 has a plurality of fourth power storage cells 241. The plurality of fourth power storage cells 241 are arranged in the second direction. The fourth power storage cells 241 are arranged with respect to the second power storage cells 221 on the opposite side to the side on which the above-mentioned first power storage cells 211 included in the first power storage stack 21 are located. The fourth power storage cell 241 includes a sidewall portion on the side opposite to the side on which the second power storage cells 221 are located, and external terminals of mutually opposite polarities are provided on the sidewall portion.

[0125] The first storage cell 211, the second storage cell 221, the third storage cell 231, and the fourth storage cell 241 have substantially the same configuration. The first storage cell 211, the second storage cell 221, the third storage cell 231, and the fourth storage cell 241 have a rectangular tubular shape that is flattened in the second direction.

[0126] The energy storage device 10C includes a cooler 70. The cooler 70 is provided in each energy storage module 20. The cooler 70 is disposed between energy storage stacks adjacent to each other in the second direction in each energy storage module 20 so as to cool both of the energy storage stacks adjacent to each other in the second direction. For example, in an energy storage module 20 located on one side in the first direction, the cooler 70 is sandwiched between the first energy storage stack 21 and the third energy storage stack 23. Similarly, in an energy storage module 20 located on the other side in the first direction, the cooler 70 is sandwiched between the second energy storage stack 22 and the fourth energy storage stack 24. The cooler 70 has a refrigerant flow path therein through which a cooling medium flows.

[0127] Fig. 9 is a cross-sectional view taken along line IX-IX shown in Fig. 8. As shown in Fig. 9, a first exhaust valve 216 is provided on the side wall portion 213 of the first storage cell 211, and a second exhaust valve 226 is provided on the side wall portion 223 of the second storage cell 221.

[0128] Furthermore, in the cross member 40C, a first opening 47 is provided in the first wall portion 41. The first opening 47 is provided to face the first exhaust valve 216. Therefore, when gas is exhausted from the first exhaust valve 216, the gas can be introduced into the inside of the cross member 40C through the first opening 47. This allows emissions contained in the gas to remain inside the cross member 40C, and prevents the emissions from scattering.

[0129] The first opening 47 is covered by a breakable heat insulating member 60. The heat insulating member 60 faces the first exhaust valve 216 in the first direction.

[0130] A second opening 48 is provided in the second wall portion 42. The second opening 48 is provided to face the second exhaust valve 226. Therefore, when gas is exhausted from the second exhaust valve 226, the gas can be introduced into the inside of the cross member 40C through the second opening 48. This allows emissions contained in the gas to remain inside the cross member 40C, and prevents the emissions from scattering.

[0131] The second opening 48 is covered by a breakable heat insulating member 60. The heat insulating member 60 faces the second exhaust valve 226 in the first direction.

[0132] The partition wall 45 is provided to stand upright from the bottom wall portion 44. The partition wall 45 is provided so as not to reach the upper wall portion 43. The upper end of the partition wall 45 is located above the first opening 47 and the second opening 48.

[0133] The cross member 40C is also provided with a communication portion 49. Specifically, the communication portion 49 is provided, for example, in the upper wall portion 43. The communication portion 49 may be provided above the first exhaust valve 216 and the second exhaust valve 226, or above the first storage cell 211 and the second storage cell 221.

[0134] The communication portion 49 communicates the hollow portion H with the space around the cross member 40. More specifically, the communication portion 49 communicates the hollow portion H with the space inside the accommodating case 30. The communication portion 49 extends along the second direction.

[0135] The cross member 40C has a first end and a second end at opposite ends in the second direction, and the communication portion 49 extends continuously from the first end toward the second end.

[0136] Note that communication portion 49 may have a shape that extends intermittently in the second direction in correspondence with each of the power storage modules 20 lined up in the second direction. In this case, the length of communication portion 49 in the second direction at a location corresponding to each power storage module 20 (specifically, a portion of cross member 40 facing each power storage module 20) is, for example, equal to or greater than the length in the second direction from one of first exhaust valves 216 included in each of the first power storage cells 211 that is located on one side in the second direction to the other of each of the first exhaust valves 216 that is located on the other side in the second direction.

[0137] FIG. 10 is a plan view of a heat insulating member that covers an opening of a cross member in an energy storage device according to the second embodiment.

[0138] As shown in Fig. 10, the heat insulating member 60 is provided in a sheet shape. The heat insulating member 60 is made of, for example, a mica sheet. The heat insulating member 60 is provided with an easily breakable portion 61. The easily breakable portion 61 is made of, for example, a break line. The break line is formed by through holes arranged in a ring or frame shape. In the heat insulating member 60, the first exhaust valve 216 or the second exhaust valve 226 faces the area surrounded by the break line in the first direction. Note that the first exhaust valve 216 or the second exhaust valve 226 may face the break line in the first direction.

[0139] Furthermore, the heat insulating member 60 is not limited to a mica sheet, and may be made of a resin sheet having lower heat insulating strength than the mica sheet. In this case, the easily breakable portion 61 may be omitted.

[0140] The heat insulating member 60 facing the first exhaust valve 216 is configured to be rupturable by the exhaust discharged from the first exhaust valve 216. On the other hand, when exhaust is not discharged from the first exhaust valve 216 but is discharged from the second exhaust valve 226, it is preferable that the heat insulating member 60 facing the first exhaust valve 216 is not ruptured by the exhaust from the second exhaust valve 226.

[0141] Similarly, the heat insulating member 60 facing the second exhaust valve 226 is configured to be rupturable by the exhaust discharged from the second exhaust valve 226. On the other hand, when exhaust is not discharged from the second exhaust valve 226 but is discharged from the first exhaust valve 216, it is preferable that the heat insulating member 60 facing the second exhaust valve 226 is not ruptured by the exhaust from the first exhaust valve 216.

[0142] FIG. 11 is a schematic cross-sectional view illustrating movement of discharged matter discharged from the second energy storage cell in the energy storage device according to the second embodiment.

[0143] 11 , when emissions are discharged from the second exhaust valve 226 of the second energy storage cell 221, the insulating member 60 facing the second exhaust valve 226 is broken, and the emissions are introduced into the inside of the cross member 40C. Note that the insulating member 60 is provided with the easily breakable portion 61, so that the insulating member 60 is easily broken by the force of the emissions. Furthermore, since the second exhaust valve 226 faces the break line that constitutes the easily breakable portion 61 or the area surrounded by the break line, the insulating member 60 can be broken more reliably.

[0144] By arranging the partition wall 45 so that the second exhaust valve 226 overlaps with the partition wall 45 in the first direction, the discharged matter introduced through the second opening 48 can be first moved toward the partition wall 45. This prevents the discharged matter from heading directly toward the first energy storage cell 211 and prevents the discharged matter from scattering while still in a high temperature state. Furthermore, the discharged matter can be collected in the lower part of the hollow portion H (more specifically, on the bottom wall portion 44 side of the cross member 40C). This prevents the discharged matter from scattering into the space within the storage case 30.

[0145] Furthermore, the first opening 47 located on the opposite side to the second opening 48 is covered with the heat insulating member 60, and the heat insulating member 60 can suppress the heat directed from the first opening 47 to the first energy storage cell 211. This makes it possible to suppress a rise in the temperature of the first energy storage cell 211.

[0146] Furthermore, since the cross member 40C is provided with the above-mentioned communication portion 49, gas introduced into the cross member 40C is discharged to the space around the cross member 40C (inside the housing case 30) through the communication portion 49. This makes it possible to prevent the internal pressure of the cross member 40C from increasing excessively.

[0147] If the internal pressure of the cross member 40C rises excessively while the internal pressure of the storage case 30 does not rise, the internal pressure of the storage case 30 may not reach a predetermined pressure, and the discharge part 80 provided in the upper member 31 may not open. Here, in this embodiment, as described above, gas is discharged into the storage case 30 from the communication part 49, thereby increasing the internal pressure of the storage case 30 and reliably opening the discharge part 80.

[0148] In addition, since the communication portions 49 are provided in the upper wall portion 43, gas in the cross member 40C can be discharged upward. This prevents the gas discharged from the communication portions 49 from directly blowing against the energy storage module 20 (the first energy storage cells 211 and the second energy storage cells 221). As a result, a temperature rise in the energy storage module 20 due to the gas discharged from the communication portions 49 can be suppressed. A gap is provided between the upper wall portion 43 and the upper member 31, and the gas is discharged toward this gap.

[0149] Although the above description has been given of a case where gas is discharged from the second energy storage cell 221, substantially the same effect as described above can be obtained when gas is discharged from the first energy storage cell 211. For example, when gas is discharged from the first energy storage cell 211, the insulating member 60 covering the first opening 47 breaks, allowing the gas to be introduced into the first opening 47. This allows the discharged gas to remain inside the cross member 40C and prevent the discharged gas from scattering into the housing case 30. Furthermore, because the second opening 48 located on the opposite side from the first opening 47 is covered with the insulating member 60, heat directed from the second opening 48 to the second energy storage cell 221 can be suppressed. The effect of gas discharge from the communication portion 49 is similar to that described above.

[0150] Furthermore, in the second embodiment, as in the first embodiment, a partition wall 45 is provided on the cross member 40C, and as a result, the energy storage device 10C of the second embodiment achieves substantially the same effects as the energy storage device 10 of the first embodiment.

[0151] In addition, as described above, by providing the cooler 70 between the first storage cell 211 and the third storage cell 231, even if heat is transferred from the second storage cell 221 side to the first storage cell 211, the cooler 70 can cool the first storage cell 211 and prevent the heat from being transferred to the third storage cell 231.

[0152] Similarly, by providing a cooler 70 between the second storage cell 221 and the fourth storage cell 241, even if heat is transferred from the first storage cell 211 to the second storage cell 221, the cooler 70 can cool the second storage cell 221 and prevent the heat from being transferred to the fourth storage cell 241.

[0153] (Third Modification) Fig. 12 is a cross-sectional view showing a cross member and its surrounding structure according to a third modification. Referring to Fig. 12, a power storage device 10D according to the third modification will be described.

[0154] 12, a power storage device 10D according to the third modification is different from the power storage device 10C according to the second embodiment in the configuration of a cross member 40D. The other configurations are substantially the same.

[0155] The cross member 40D is formed by bending a plate-like member made of a metal such as SUS, etc. The cross member 40D is manufactured by roll forming.

[0156] Specifically, the cross member 40D is configured by bending the single plate-like member so as to connect, in this order, the partition wall 45, the first wall portion 41, the bottom wall portion 44, and the second wall portion 42. More specifically, the single plate-like member sequentially connects the lower end 45a of the partition wall 45, the upper end of the partition wall 45, the upper end of the first wall portion 41, the lower end of the first wall portion 41, the lower end of the second wall portion 42, and the upper end of the second wall portion 42, and is bent from the upper end of the second wall portion 42 toward the upper end of the partition wall 45.

[0157] The upper wall portion 43 is formed by a connection portion connecting the upper end of the partition wall 45 and the upper end of the first wall portion 41, and a portion bent from the upper end of the second wall portion 42 toward the upper end of the partition wall 45. A gap is formed between the upper end of the partition wall 45 and the portion bent from the upper end of the second wall portion 42 toward the upper end of the partition wall 45, and this gap forms a communication portion 49.

[0158] The bottom wall 44 is formed by a portion connecting the lower end of the first wall 41 and the lower end of the second wall 42. The bottom wall 44 functions as a bottom surface defining portion that defines the bottom surface of the hollow portion H, and a gap is formed between the bottom wall 44 and the lower end 45a of the partition wall 45. The lower end 45a of the partition wall 45 is a free end. The lower end 45a of the partition wall 45 is located at a position lower than the first exhaust valve 216 and the second exhaust valve 226.

[0159] Even when configured as described above, the power storage device 10D according to the third modification achieves substantially the same effects as the power storage device 10C according to the second embodiment. Specifically, as in the second embodiment, the partition wall 45 is disposed so as to overlap the first exhaust valve 216 or the second exhaust valve 226 in the first direction, thereby allowing the discharged matter introduced through the first opening 47 or the second opening 48 to first move toward the partition wall 45. This prevents the discharged matter from moving directly toward the first energy storage cell 211 or the second energy storage cell 221, while preventing the discharged matter from scattering while still in a high temperature state. In addition, as described above, a gap is formed between the partition wall 45 and the lower end 45a of the partition wall 45, allowing the discharged matter introduced into the cross member 40D through the first opening 47 or the second opening 48 to be stored (collected) in the gap. Furthermore, a sufficient amount of the discharged matter can be stored.

[0160] (Fourth Modification) Fig. 13 is a cross-sectional view showing a cross member and its surrounding structure according to a fourth modification. Referring to Fig. 13, a power storage device 10E according to the fourth modification will be described.

[0161] 13 , a power storage device 10E according to the fourth modification differs from a power storage device 10D according to the third modification in the positions of a first exhaust valve 216, a second exhaust valve 226, a first opening 47, and a second opening 48. The other configurations are substantially the same.

[0162] The first exhaust valve 216 and the second exhaust valve 226 are disposed so as to be offset in the vertical direction when viewed from the first direction. Specifically, the first exhaust valve 216 is disposed vertically above the center of the side wall portion 213. The second exhaust valve 226 is disposed vertically below the center of the side wall portion 223.

[0163] A first opening 47 and a second opening 48 are provided in the cross member 40E to correspond to the first exhaust valve 216 and the second exhaust valve 226. Specifically, the first opening 47 is provided above the center of the first wall portion 41 in the vertical direction so as to face the first exhaust valve 216 in the first direction. The second opening 48 is provided below the center of the second wall portion 42 in the vertical direction so as to face the second exhaust valve 226 in the first direction.

[0164] Alternatively, the first exhaust valve 216 and the first opening 47 may be provided on the lower side, and the second exhaust valve 226 and the second opening 48 may be disposed on the upper side.

[0165] Even when configured as described above, the power storage device 10E according to the fourth modification can achieve substantially the same effects as the power storage device 10D according to the third modification. In addition, as described above, the first opening 47 and the second opening 48 are arranged to be offset in the vertical direction when viewed from the first direction, so that even when gas is introduced through one of the first opening 47 and the second opening 48, the gas can be prevented from flowing directly toward the other opening.

[0166] (Fifth Modification) Fig. 14 is a cross-sectional view showing a cross member and its surrounding structure according to a fifth modification. Referring to Fig. 14, a power storage device 10F according to the fifth modification will be described.

[0167] As shown in FIG. 14, a power storage device 10F according to the fifth modification is different from a power storage device 10C according to the second embodiment in the position of a communication portion 49.

[0168] The height of the cross member 40C in the vertical direction is greater than the height of the first storage cell 211 and the second storage cell 221 in the vertical direction, and the communication portion 49 is provided above the first storage cell 211 and the second storage cell 221. Specifically, the communication portion 49 is provided in a portion of the first wall portion 41 and the second wall portion 42 that is located above the first storage cell 211 and the second storage cell 221. Note that the communication portion 49 may be provided in either the first wall portion 41 or the second wall portion 42.

[0169] Even when configured as described above, the energy storage device 10F according to the fifth modification can achieve substantially the same effects as the energy storage device 10C according to embodiment 2. Furthermore, when the cross member according to the fifth modification is employed, if there is not a sufficient gap between the upper wall portion 43 of the cross member and the upper member 31, gas can be effectively discharged toward the space located above the first energy storage cell 211 and the second energy storage cell 221.

[0170] (Embodiment 3) Fig. 15 is an exploded perspective view of a power storage device according to embodiment 3. A power storage device 10G according to embodiment 3 will be described with reference to Fig. 15 .

[0171] 14 , when compared with power storage device 10C according to embodiment 2, power storage device 10G according to embodiment 3 differs in the positions of first exhaust valve 216, second exhaust valve 226, first opening 47, and second opening 48. The other configurations are substantially the same.

[0172] The first exhaust valves 216 provided in each of the plurality of first storage cells 211 arranged in the second direction are arranged alternately up and down along the second direction. Accordingly, the plurality of first openings 47 provided corresponding to the plurality of first storage cells 211 are also arranged alternately up and down along the second direction.

[0173] Similarly, the second exhaust valves 226 provided in each of the second energy storage cells 221 arranged in the second direction are arranged alternately up and down along the second direction. Accordingly, the second openings 48 provided corresponding to the second energy storage cells 221 are also arranged alternately up and down along the second direction.

[0174] In the first storage cell 211 and the second storage cell 221 that face each other in the first direction, the first exhaust valve 216 and the second exhaust valve 226 are arranged so as to be offset in the vertical direction when viewed from the first direction.

[0175] Even when configured in this manner, the power storage device 10G according to the third embodiment can achieve substantially the same effects as the power storage device 10C according to the second embodiment.

[0176] (Fourth embodiment) Fig. 16 is a plan view showing the inside of a power storage device according to a fourth embodiment. With reference to Fig. 16, a power storage device 10H according to the fourth embodiment will be described.

[0177] The power storage stack 10H according to the fourth embodiment differs from the power storage stack 10 according to the first embodiment in the arrangement of the cross member 40 and the electronic devices 96, 97. The other configurations are substantially the same.

[0178] Two cross members 40 are arranged side by side in the first direction with a gap between them between the first storage stack 21 and the second storage stack 22, and electronic devices 96, 97 are arranged between the two cross members 40.

[0179] That is, the first power storage stack 21 and the electronic devices 96, 97 are arranged side by side in the first direction, and one cross member 40 is arranged between the first power storage stack 21 and the electronic devices 96, 97. The electronic devices 96, 97 and the second power storage stack 22 are arranged side by side in the first direction, and the other cross member 40 is arranged between the electronic devices 96, 97 and the second power storage stack 22. The electronic device 96 controls, for example, the operation of the first power storage stack 21, and the electronic device 97 controls, for example, the operation of the second power storage stack 22. Note that, although the present embodiment illustrates an example in which two electronic devices 96, 97 are provided, the number of electronic devices may be one or three or more.

[0180] Even when configured as described above, the cross member 40 is disposed between the first power storage stack 21 and the second power storage stack 22, and therefore the power storage device 10H according to embodiment 4 can obtain substantially the same effects as the device 1 according to embodiment 1. Furthermore, when any first power storage cell 211 included in the first power storage stack 21 or any second power storage cell 221 included in the second power storage stack 22 generates heat, the radiant heat from the first power storage cell 211 or the second power storage cell 221 is prevented from being transmitted to the electronic devices 96, 97, and a temperature rise in the electronic devices 96, 97 can be suppressed.

[0181] In the above description, the case where the electronic devices 96, 97 are arranged between the first power storage stack 21 and the second power storage stack 22 has been exemplified, but the present invention is not limited to this. The electronic devices 96, 97 may be arranged such that the cross member 40 is located between the electronic devices 96, 97 and the first power storage stack 21 or the second power storage stack 22. As long as the electronic devices 96, 97 are arranged in this manner, one of the first power storage stack 21 or the second power storage stack 22 may be omitted.

[0182] Fifth Embodiment Fig. 17 is a cross-sectional view showing a cross member and its surrounding structure according to a fifth embodiment. A power storage device 10I according to the fifth embodiment will be described with reference to Fig. 17 .

[0183] 17, an energy storage device 10I according to the fifth embodiment differs from energy storage device 10 according to the first embodiment in the shape of cross members 40. The other configurations are substantially the same.

[0184] In the fifth embodiment, the cross member 40 does not have a bottom wall portion, but has flange portions 41f, 42f that extend outward from the lower ends of the first wall portion 41 and the second wall portion 42. The flange portions 41f, 42f are fixed to the bottom wall portion 321 of the accommodation case 30. The flange portions 41f, 42f may be fixed to the bottom wall portion 321 with fastening members, or may be fixed to the bottom wall portion 321 by welding or the like. In this case, the portion of the bottom wall portion 321 of the accommodation case 30 that faces the upper wall portion 43 in the up-down direction functions as a bottom surface defining portion that defines the bottom surface of the hollow portion H.

[0185] Even when configured as described above, the power storage device 10I according to the fifth embodiment can achieve substantially the same effects as the device 1 according to the first embodiment.

[0186] The configuration of the cross member having flange portions 41f, 42f as shown in Figure 17 may be applied to the cross members of embodiments 2, 3, and 4, as well as the first, second, and fifth modified examples.

[0187] (Other Modifications) In the first, second, third, fourth, and fifth embodiments and the first to fifth modifications described above, the first exhaust valve 216 and the second exhaust valve 226 are disposed opposite the cross member, but this is not limiting. The first storage cell 211 and the second storage cell 221 may be disposed so that the first exhaust valve 216 and the second exhaust valve 226 do not face the cross member. In this case, by disposing the cross member as described above between the first storage cell 211 and the second storage cell 221, it is possible to reduce the effect of radiant heat from one storage cell on the other storage cell while suppressing an increase in weight.

[0188] Furthermore, other members such as a bus bar module or a bus bar cover may be interposed between the first power storage stack 21 or the second power storage stack 22 and the cross member. More particularly, a bus bar cover may be disposed between the first exhaust valve 216 or the second exhaust valve 226 and the cross member. In this case, if the bus bar cover is melted and damaged by emissions discharged from the first exhaust valve 216 or the second exhaust valve 226, the cross member can prevent the emissions from scattering through the melted and damaged portion.

[0189] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, and includes meanings equivalent to the claims and all modifications within the scope of the claims.

[0190] REFERENCE SIGNS LIST 1 vehicle, 2 vehicle body, 3 front wheel, 4 rear wheel, 5 frame member, 6 side member, 7 side sill, 8 fastening member, 9 cross frame member, 10, 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 10I energy storage device, 10a upper surface, 20 energy storage module, 21 first energy storage stack, 22 second energy storage stack, 23 third energy storage stack, 24 fourth energy storage stack, 25 electrode body, 30 housing case, 31 upper member, 32 lower member, 35 main body portion, 36 fixed portion, 40, 40A, 40B, 40C, 40D, 40E cross member, 41 first wall portion, 41f flange portion, 42 second wall portion, 42f flange portion, 43 upper wall portion, 44 bottom wall portion, 45 Partition wall, 45a lower end, 47 first opening, 48 second opening, 49 communicating portion, 50 partition wall, 60 heat insulating member, 61 easily breakable portion, 70 cooler, 80 discharge portion, 95 electronic device, 211 first storage cell, 212 housing, 213 side wall portion, 213A, 213B external terminal, 216 first exhaust valve, 221 second storage cell, 222 housing, 223 side wall portion, 223A, 223B external terminal, 226 second exhaust valve, 231 third storage cell, 241 fourth storage cell, 321 bottom wall portion, 322 front wall portion, 323 rear wall portion, 324, 325 side wall portion, H hollow portion, S1, S2 projected area, T1, T2 thickness.

Claims

1. A storage device comprising: first and second storage cells arranged side by side and spaced apart in a first direction; and a cross member extending along a second direction perpendicular to the first direction and arranged between the first and second storage cells, wherein the cross member has a hollow portion in a cross section perpendicular to the second direction, and the cross member has a first wall portion facing the first storage cells in the first direction, and a partition wall that intersects the first direction in the cross section and separates the hollow portion, and at least a portion of the partition wall has an area with a higher reflectivity than the first wall portion.

2. The electricity storage device according to claim 1, wherein the thickness of the partition wall is equal to or less than the thickness of the first wall portion.

3. The energy storage device according to claim 1, wherein the partition wall has a projected area in the first direction that is 25% or more and 100% or less of the projected area of ​​the first wall portion in the first direction.

4. The energy storage device according to claim 1, wherein the smaller of the intersection angles between the first direction and the partition wall is equal to or greater than 45 degrees and less than 90 degrees, or the intersection angle is 90 degrees.

5. The energy storage device according to any one of claims 1 to 4, wherein the first energy storage cell has a first exhaust valve, and the first exhaust valve faces the cross member in the first direction.

6. The energy storage device according to claim 5, wherein the second energy storage cell has a second exhaust valve, and the second exhaust valve faces the cross member in the first direction.

7. The electricity storage device according to claim 5, wherein the first exhaust valve is arranged to overlap the partition wall when viewed from the first direction.

8. The electricity storage device according to claim 7, wherein the first wall portion is provided with a first opening at a position opposite the first exhaust valve.

9. The electricity storage device according to claim 8, wherein the first opening is covered with a breakable heat insulating member.

10. The electricity storage device according to claim 9, wherein the heat insulating member has an easily breakable portion.

11. The electricity storage device according to claim 10, wherein the easily breakable portion is configured by a break line, and the first exhaust valve is disposed opposite the break line in the first direction.

12. The electric storage device described in claim 8, wherein the cross member is provided with a communication portion that connects the hollow portion with the space surrounding the cross member, and the communication portion is provided in a position that does not face the first exhaust valve.

13. The energy storage device according to claim 12, further comprising a bottom surface defining portion that defines the bottom surface of the hollow portion, wherein the end of the partition wall that is located on the bottom surface defining portion side is a free end, and a gap is provided between the free end and the bottom surface defining portion.

14. The electricity storage device according to claim 12, wherein the communication portion is provided above the first exhaust valve in a vertical direction perpendicular to the first direction and the second direction.

15. The energy storage device according to claim 14, wherein the height of the cross member in the vertical direction is greater than the height of the first energy storage cell and the second energy storage cell in the vertical direction, and the communication portion is provided above the first energy storage cell and the second energy storage cell.

16. The electricity storage device according to claim 14, wherein the cross member has an upper wall portion in the vertical direction, and the communication portion is provided in the upper wall portion.

17. The power storage device according to any one of claims 1 to 4, wherein the partition wall has a plurality of wall portions arranged at intervals in the first direction.

18. A storage device according to any one of claims 1 to 4, further comprising: a third storage cell arranged on the opposite side of the first storage cell from the side on which the second storage cell is located in the first direction; and a cooler arranged in a gap between the first storage cell and the third storage cell, for cooling the first storage cell and the third storage cell.

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