Power storage device

Abstract

To provide a power storage device which can suppress scattering of discharge contained in gas ejected from the heated power storage cell.SOLUTION: A power storage device 10 comprises: a first power storage cell 211 and a second power storage cell 221 which are arrayed in a first direction; and a cross member 40 which extends in a second direction orthogonal to the first direction to be arranged in a gap between the first power storage cell 211 and the second power storage cell 221. The first power storage cell 211 includes a first lateral wall part 213 facing the cross member 40. The first lateral wall part 213 includes a first exhaust valve 216. The cross member 40 includes a hollow part H and a first opening part 47 facing the first lateral wall part 213. The cross member 40 includes a communication part 49 which communicates the hollow part H with space around the cross member 40. The communication part 49 is arranged at a position that does not face with the first exhaust valve 216.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] As a conventional electricity storage device, Japanese Patent Application Laid-Open No. 2023-165300 (Patent Document 1) discloses a cross member that divides the space inside a battery case into a plurality of regions, and an electricity storage module is disposed in each of the plurality of regions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-165300 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, a power storage module includes multiple power storage cells, each with its own exhaust valve. When one power storage cell generates heat, emissions are released from the exhaust valve of the heated power storage cell. The emissions contain gases, electrolytes, etc., and if no measures are taken, the emissions accumulate in the area where the heated power storage module is located. This can cause the emissions to adhere to the power storage module, resulting in a short circuit.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and an object of the present disclosure is to provide an electricity storage device that can suppress the scattering of waste materials emitted from heated electricity storage cells. [Means for solving the problem]

[0006] An energy storage device according to the present disclosure includes a first energy storage cell and a second energy storage cell 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 in a gap between the first energy storage cell and the second energy storage cell. The first energy storage cell has a first side wall portion facing the cross member. A first exhaust valve is provided in the first side wall portion. The cross member has a hollow portion in a cross section perpendicular to the second direction, and a first opening portion facing the first side wall portion. The cross member has a communication portion that communicates the hollow portion with a space surrounding the cross member. The communication portion is provided in a position that does not face the first exhaust valve.

[0007] According to the above configuration, when the first energy storage cell generates heat and exhaust is discharged from the first exhaust valve, the exhaust can be introduced into the hollow portion of the cross member through the first opening provided in the cross member so as to face the first energy storage cell. This allows the exhaust to be collected inside (the hollow portion of) the cross member. As a result, scattering of the exhaust discharged from the heated energy storage cell can be suppressed.

[0008] Furthermore, the exhaust material includes gas. By discharging the gas introduced into the cross member through the first opening through a communication portion located in a position not facing the first exhaust valve, an excessive increase in the internal pressure of the cross member due to the gas introduced into the cross member through the first opening can be prevented. Generally, if the internal pressure of the cross member increases excessively, a portion of the cross member may deform or break, causing gas to be ejected from unintended locations, potentially causing the exhaust material trapped within the cross member to be blown out. However, by providing the communication portion as described above, an excessive increase in the internal pressure of the cross member can be prevented, thereby preventing the exhaust material from being ejected from unintended locations. This also helps prevent the exhaust material from scattering from the heated energy storage cells.

[0009] In the electricity storage device according to the present disclosure, the first opening may be disposed opposite the first exhaust valve.

[0010] According to the above configuration, the exhaust material is discharged from the first exhaust valve directly toward the first opening, so that the exhaust material can be introduced directly into the cross member while preventing the exhaust material from being dispersed around the energy storage module, thereby further preventing the exhaust material from scattering.

[0011] In the energy storage device according to the present disclosure, the second energy storage cell may have a second sidewall portion facing the cross member. The second sidewall portion may be provided with a second exhaust valve. In this case, the cross member may be provided with a second opening portion facing the second sidewall portion.

[0012] According to the above configuration, when the second energy storage cell generates heat and exhaust is discharged from the second exhaust valve, the exhaust can be introduced into the hollow portion of the cross member through the second opening provided in the cross member so as to face the second energy storage cell. This allows the exhaust to be collected inside (the hollow portion of) the cross member. As a result, it is possible to suppress the dispersion of the exhaust contained in the gas discharged from the heated energy storage cell.

[0013] In the power storage device according to the present disclosure, the first opening and the second opening may be covered with a breakable heat insulating member.

[0014] According to the above configuration, when waste is discharged from the first exhaust valve of the first energy storage cell, the heat insulating member is broken by the force of the discharged waste. This allows the waste to be introduced into the cross member through the first opening and collected inside the cross member. Furthermore, by providing the heat insulating member at the second opening, heat from the waste introduced through the first opening can be prevented from being transferred to the second energy storage cell through the second opening. This prevents a temperature rise in the second energy storage cell.

[0015] On the other hand, when waste is discharged from the second exhaust valve of the second energy storage cell, the force of the discharged waste breaks the insulating member. This allows the waste to be introduced into the cross member through the second opening and collected inside the cross member. Furthermore, by providing the insulating member at the first opening, heat from the waste introduced through the second opening can be prevented from passing through the first opening to the first energy storage cell. This prevents the temperature of the first energy storage cell from rising.

[0016] In the power storage device according to the present disclosure, the heat insulating member may be provided with an easily breakable portion.

[0017] According to the above configuration, when waste is discharged from the exhaust valve of one of the first and second storage cells, the heat insulating member located on the side of the one storage cell can be more reliably broken.

[0018] In the energy storage device based on the present disclosure, the first opening and the second opening may be arranged offset in a vertical direction perpendicular to the first direction and the second direction when viewed from the first direction.

[0019] According to the above configuration, even when the discharged matter is introduced through one of the first opening and the second opening, the discharged matter can be prevented from heading directly toward the other opening.

[0020] In the power storage device based on 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.

[0021] 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, it can be discharged above the first exhaust valve, thereby preventing the gas discharged from the communication portion from blowing against the first exhaust valve.

[0022] In the energy storage device according to the present disclosure, the cross member may have a height in the vertical direction greater than the heights of the first and second energy storage cells, and in this case, the communication portion may be provided above the first and second energy storage cells.

[0023] 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 preventing the gas from the communication portion from blowing against the first and second energy storage cells and suppressing a rise in temperature of the first and second energy storage cells.

[0024] In the power storage device according to the present disclosure, the cross member may have an upper wall portion on the upper side in the vertical direction, and the communication portion may be provided in the upper wall portion.

[0025] 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, the gas is discharged upward from the upper wall portion, which prevents the gas from the communication portion from blowing against the first and second energy storage cells and prevents a rise in temperature of the first and second energy storage cells.

[0026] The energy storage device according to the present disclosure may include a first energy storage module in which a plurality of the first energy storage cells are arranged in the second direction, and a second energy storage module in which a plurality of the second energy storage cells are arranged in the second direction. The cross member may be disposed between the first energy storage module and the second energy storage module. The length of the communication portion in the second direction may be equal to or greater than the length in the second direction from a first exhaust valve located on one side in the second direction among the first exhaust valves of each of the plurality of first energy storage cells to a first exhaust valve located on the other side in the second direction among the first exhaust valves.

[0027] According to the above configuration, since the communication portion is provided over a wide area, even when exhaust is discharged from the first exhaust valve of any first energy storage cell included in the first energy storage module, gas contained in the exhaust introduced into the cross member from the first opening can be stably discharged from the communication portion, thereby preventing an excessive increase in the internal pressure of the cross member.

[0028] The energy storage device according to 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 a 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.

[0029] 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. [Effects of the Invention]

[0030] According to the present disclosure, it is possible to provide an electricity storage device that can suppress scattering of waste matter discharged from heated electricity storage cells. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a schematic diagram of a vehicle equipped with an electricity storage device according to a first embodiment. [Figure 2] 1 is a diagram showing a state in which the power storage device according to the first embodiment is fixed to a vehicle. [Figure 3] 1 is a plan view showing the inside of the electricity storage device according to the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. [Figure 5] 4 is a plan view of a heat insulating member that covers an opening of a cross member in the electricity storage device according to the first embodiment. FIG. [Figure 6]5 is a schematic cross-sectional view showing the movement of discharged matter discharged from a second power storage cell in the power storage device according to the first embodiment. FIG. [Figure 7] FIG. 10 is a cross-sectional view showing a cross member and its surrounding structure according to a first modified example. [Figure 8] FIG. 10 is a cross-sectional view showing a cross member and its surrounding structure according to a second modified example. [Figure 9] FIG. 10 is an exploded perspective view of an electricity storage device according to a second embodiment. [Figure 10] FIG. 10 is a plan view showing the inside of a power storage device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0033] 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.

[0034] (Embodiment 1) Fig. 1 is a schematic diagram of a vehicle equipped with a power storage device according to embodiment 1. Fig. 2 is a diagram showing a state in which the power storage device according to embodiment 1 is fixed to a vehicle. Vehicle 1 according to embodiment 1 will be described with reference to Figs. 1 and 2.

[0035] The vehicle 1 is a hybrid vehicle that can run using at least one of the power of a motor and an engine, or an electric vehicle that runs using driving force obtained from electrical energy.

[0036] The vehicle 1 includes a vehicle body 2, front wheels 3, rear wheels 4, and a power storage device 10. The vehicle body 2 includes a frame member 5. The power storage device 10 is disposed below the vehicle body 2. The power storage device 10 is disposed, for example, between the front wheels 3 and the rear wheels 4. Note that a portion of the power storage device 10 may be disposed overlapping at least one of the front wheels 3 and the rear wheels 4 when viewed from the width direction of the vehicle 1. The power storage device 10 has an upper surface 10a. The upper surface 10a may function as a floor member that defines the interior of the vehicle cabin.

[0037] 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.

[0038] The pair of side members 6 are spaced apart in the width direction of the vehicle 1. A main body 35 of the electricity storage device 10 is disposed in the gap between the pair of side members 6. A gap is provided between the main body 35 and the pair of side members 6. This makes it possible to suppress input of an impact to the electricity storage device 10 even in the event of a side collision of the vehicle 1.

[0039] 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.

[0040] The framework member 5 also includes a cross framework member 9. The cross framework member 9 is provided above the electricity storage device 10 so as to straddle from one side sill 7 to the other side sill 7. To the cross framework member 9, an upper surface 10a of the electricity storage device 10 is fixed.

[0041] In the above description, the framework member 5 includes a pair of side members 6 and a pair of side sills 7, but is not limited to this. The pair of side sills 7 may also function as the pair of side members 6. In this case, the pair of side members 6 can be omitted, and the above-mentioned fixed portion 36 may be fixed to the pair of side sills 7.

[0042] 3 is a plan view showing the inside of the power storage device according to Embodiment 1. With reference to FIG.

[0043] As shown in FIG. 3, the power storage device 10 includes a plurality of power storage modules 20, a housing case 30, a plurality of cross members 40, and electronic equipment 95.

[0044] The plurality of power storage modules 20 include a first power storage module 21 and a second power storage module 22. The first power storage module 21 and the second power storage module 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.

[0045] The first power storage module 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) 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 module 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.

[0046] 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.

[0047] 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 those that include manufacturing errors such as tolerances. Furthermore, the first storage cell 211 and the second storage cell 221 may be configured as different storage cells.

[0048] 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). Each of the housings 212, 222 houses one or more electrode bodies 25 (see FIG. 4).

[0049] 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.

[0050] 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.

[0051] 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.

[0052] The storage case 30 includes an upper member 31 (see FIG. 4) and a lower member 32 serving as a lower case. The lower member 32 has a generally box-like shape that opens upward. The lower member 32 includes a main body portion 35 and a fixed portion 36. The main body portion 35 has a bottom wall portion 321, a front wall portion 322, a rear wall portion 323, and side walls 324 and 325. The front wall portion 322, the rear wall portion 323, and the side walls 324 and 325 are provided to stand upright from the periphery of the bottom wall portion 321.

[0053] 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.

[0054] A plurality of cross members 40 are fixed to the lower member 32. The 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 storage space within the storage case 30 is divided into three sections in the first direction by two cross members 40.

[0055] In each of the three divided areas, an electronic device 95, a first power storage module 21, and a second power storage module 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 module 21, and a cross member 40 is arranged in the gap between the first power storage module 21 and the second power storage module 22.

[0056] The number of cross members 40 is not limited to two, and may be one, or three or more, as long as they are arranged in the gap between the adjacent first power storage module 21 and second power storage module 22. The cross member 40 is made of a metal member such as SUS, for example.

[0057] At least one of the multiple cross members 40 that is disposed in the gap between the first energy storage module 21 and the second energy storage module 22 has a hollow portion H (see FIG. 4 ). Note that the multiple cross members 40 may all have a hollow portion H. The hollow portion H may form part of a smoke exhaust path for gas that is discharged when heat is generated by any of the energy storage cells included in the first energy storage module 21 and the second energy storage module 22.

[0058] 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 shape that opens downward. The upper member 31 may also be provided with an exhaust section 80 (see FIG. 9 ) for exhausting gas inside the housing case 30 when the internal pressure inside the housing case 30 exceeds a predetermined pressure. When the exhaust section 80 is provided, the vehicle 1 is configured so that gas exhausted from the exhaust section 80 is not introduced into the interior of the vehicle 1.

[0059] The electronic device 95 controls the plurality of power storage modules 20. The electronic device 95 is, for example, a battery ECU.

[0060] Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3, and more specifically, a cross-sectional view showing the cross member and its surrounding structure. For convenience, Fig. 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 Fig. 4.

[0061] 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 also has a first opening 47, a second opening 48, and a communication portion 49. The cross member 40 includes a first wall portion 41, a second wall portion 42, an upper wall portion 43, and a bottom wall portion 44.

[0062] The first wall portion 41 is located on one side in the first direction. The first wall portion 41 faces the first energy storage cell 211 in the first direction. A first opening 47 is provided in the first wall portion 41. The first opening 47 is provided so as to face the first energy storage cell 211. More specifically, the first opening 47 is arranged so as to face a first exhaust valve 216, which will be described later. Note that a plurality of first openings 47 are provided side by side in the second direction, and each of the plurality of first openings 47 faces a corresponding energy storage cell 211.

[0063] The second wall portion 42 is located on the other side in the first direction. The second wall portion 42 faces the second energy storage cell 221 in the first direction. A second opening 48 is provided in the second wall portion 42. The second opening 48 is provided so as to face the second energy storage cell 221. More specifically, the second opening 48 is arranged so as to face a second exhaust valve 226, which will be described later. Note that a plurality of second openings 48 are provided side by side in the second direction, and each of the plurality of second openings 48 faces a corresponding energy storage cell 211.

[0064] When viewed from the first direction, the first opening 47 and the second opening 48 are arranged so as to be offset in the vertical direction (up-down direction) perpendicular to the first direction and the second direction. Specifically, for example, when viewed from the first direction, the first opening 47 is located higher than the second opening 48. Note that the first opening 47 may also be located lower than the second opening 48 when viewed from the first direction.

[0065] The first opening 47 is covered by a heat insulating member 60, which will be described later. The second opening 48 is covered by a heat insulating member 60.

[0066] The height of the first wall portion 41 and the second wall portion 42 in the vertical direction is higher than the height of the first energy storage cell 211 and the second energy storage cell 221. Note that the height of the first wall portion 41 and the second wall portion 42 may be the same as the height of the first energy storage cell 211 and the second energy storage cell 221.

[0067] 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.

[0068] The communication portion 49 is provided at a position on the cross member 40 that does not face the first exhaust valve 216. In the present embodiment, the communication portion 49 is provided on the upper wall portion 43.

[0069] 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.

[0070] The cross member 40 has a first end and a second end at opposite ends in the second direction. The communication portion 49 extends continuously from the first end toward the second end. The length of the communication portion 49 in the second direction is, for example, equal to or greater than the length in the second direction from one of the first exhaust valves 216 included in the multiple first energy storage cells 211 in the first energy storage module 21 that is located on one side in the second direction to the other of the first exhaust valves 216 that is located on the other side in the second direction.

[0071] The communication portions 49 may have a shape that extends intermittently in the second direction in correspondence with the respective power storage modules 20 lined up in the second direction.

[0072] The housing 212 of the first storage cell 211 has a first side wall portion 213 that faces the first wall portion 41 in the first direction. An external terminal 213A and a first exhaust valve 216 are provided on the first side wall portion 213.

[0073] The first exhaust valve 216 is a valve for discharging exhaust materials from inside the first energy 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 faces the cross member 40 (more specifically, the first wall portion 41) in the first direction.

[0074] The external terminal 213A is, for example, disposed above the first exhaust valve 216. The external terminal 213A faces the first wall portion 41 in the first direction.

[0075] The housing 222 of the second storage cell 221 has a second side wall portion 223 that faces the second wall portion 42 in the first direction. An external terminal 223A and a second exhaust valve 226 are provided on the second side wall portion 223.

[0076] 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 faces the cross member 40 (more specifically, the second wall portion 42) in the first direction.

[0077] 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.

[0078] 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 provided, for example, above the center of the first side wall portion 213 in the vertical direction. The second exhaust valve 226 is provided, for example, below the center of the second side wall portion 223 in the vertical direction.

[0079] FIG. 5 is a plan view of a heat insulating member that covers an opening of a cross member in the energy storage device according to the first embodiment.

[0080] As shown in Fig. 5, 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 so as to be breakable. More specifically, the heat insulating member 60 is provided with an easily breakable portion 61.

[0081] The easily breakable portion 61 is configured by, 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.

[0082] The heat insulating member 60 is not limited to a mica sheet, and may be made of a heat insulating resin sheet having lower strength than the mica sheet. In this case, the easily breakable portion 61 may be omitted.

[0083] 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.

[0084] 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 gas from the first exhaust valve 216.

[0085] FIG. 6 is a schematic cross-sectional view showing movement of discharged matter discharged from the second power storage cell in the power storage device according to the first embodiment.

[0086] 6, when emissions are discharged from first exhaust valve 216 of first energy storage cell 211, heat insulating member 60 facing first exhaust valve 216 is broken, and the emissions are introduced into cross member 40 through first opening 47. Note that heat insulating member 60 is easily broken by the force of the emissions because heat insulating member 60 is provided with easy-to-break portion 61. Furthermore, because first exhaust valve 216 faces the area surrounded by the break line that forms easy-to-break portion 61, heat insulating member 60 can be broken more reliably.

[0087] By introducing the discharged materials into the inside of the cross member 40, the discharged materials can be collected inside the cross member (hollow portion H). In particular, discharged materials that are heavier than air accumulate on the bottom wall portion 44. This makes it possible to prevent the discharged materials discharged from the heated first energy storage cells 211 from scattering into the space around the first energy storage cells 211 and, ultimately, into the area in which the first energy storage module 21 is housed.

[0088] Furthermore, because the first opening 47 and the first exhaust valve 216 face each other in the first direction, the exhaust material is discharged from the first exhaust valve 216 directly toward the first opening 47. This makes it possible to prevent the exhaust material from diffusing around the first power storage module 21 and to introduce the exhaust material directly into the inside of the cross member 40. This further prevents the exhaust material from scattering.

[0089] Furthermore, gas contained in the exhaust introduced into the inside of the cross member 40 from the first opening 47 is discharged into the space around the cross member 40 (inside the accommodating case 30) from the communication part 49 provided in a position not facing the first exhaust valve 216. This makes it possible to prevent the internal pressure of the cross member 40 from increasing excessively due to the gas introduced into the inside of the cross member 40 from the first opening 47.

[0090] Generally, if the internal pressure of the cross member 40 rises excessively, there is a concern that part of the cross member 40 may become deformed or damaged, causing gas to be ejected from an unintended location and causing the exhaust material captured within the cross member to be blown out.

[0091] In the present embodiment, by providing communication portion 49 as described above, it is possible to suppress an excessive increase in the internal pressure of cross member 40 and to suppress the above-described blowing out of exhaust material from unintended locations. This also makes it possible to suppress scattering of exhaust material emitted from heated first energy storage cell 211.

[0092] At this time, since the communication portion 49 is provided in the upper wall portion 43 of the cross member 40, the gas inside the cross member 40 can be discharged upward. This makes it possible to prevent the gas discharged from the communication portion 49 from directly blowing against the energy storage module 20 (the first energy storage cell 211 and the second energy storage cell 221). As a result, it is possible to prevent a temperature rise in the energy storage module 20 due to the gas discharged from the communication portion 49. Note that a gap is provided between the upper wall portion 43 and the upper member 31, and the gas is discharged toward this gap.

[0093] Furthermore, the length of the communication portion 49 is equal to or greater than the length in the second direction from a first exhaust valve 216 located on one side in the second direction among the first exhaust valves 216 included in the multiple first energy storage cells 211 to a first exhaust valve 216 located on the other side in the second direction among the first exhaust valves 216. This makes it possible to stably discharge gas contained in the exhaust introduced into the cross member 40 from the first openings 47 through the communication portion 49, even when exhaust is discharged from the first exhaust valve 216 of any first energy storage cell 211 included in the first energy storage module 21. This further prevents the internal pressure of the cross member from increasing excessively.

[0094] In addition, as described above, the second opening 48 located on the opposite side to the first opening 47 is covered with the heat insulating member 60, and the heat insulating member 60 can suppress heat directed from the second opening 48 to the second energy storage cell 221. This makes it possible to suppress a rise in temperature of the second energy storage cell 221 and therefore the second energy storage module 22.

[0095] Furthermore, because the first opening 47 and the second opening 48 are arranged so as to be offset in the vertical direction when viewed from the first direction, it is possible to prevent the discharged matter introduced from the first opening 47 from heading directly toward the second opening 48. This makes it possible to prevent a rise in temperature of the second energy storage cell 221 and therefore the second energy storage module 22.

[0096] Although the above describes a case where emissions are discharged from first energy storage cell 211, substantially the same effect as described above can be obtained when emissions are discharged from second energy storage cell 221. For example, when gas is discharged from second energy storage cell 221, heat insulating member 60 covering second opening 48 breaks, allowing the emissions to be introduced into cross member 40 through second opening 48. This allows the emissions to remain within cross member 40 and prevent the emissions from scattering inside storage case 30.

[0097] Furthermore, because the first opening 47 located on the opposite side to the second opening 48 is covered with the heat insulating member 60, it is possible to suppress heat from flowing from the first opening 47 toward the first energy storage cell 211. Furthermore, because the second opening 48 is vertically offset from the first opening 47 when viewed from the first direction, it is possible to suppress the discharged matter introduced into the cross member 40 from the second opening 48 from flowing directly toward the first opening 47. The effect of gas discharge from the communication portion 49 is the same as described above.

[0098] (First Modification) 7 is a cross-sectional view showing a cross member and its surrounding structure according to the first modified example. Referring to FIG. 7, an electricity storage device 10A according to the first modified example will be described.

[0099] 7, energy storage device 10A according to the first modification differs from energy storage device 10 according to embodiment 1 in the position of communication portion 49 provided in cross member 40. The other configurations are substantially the same.

[0100] In the first modified example, the height of the cross member 40 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.

[0101] 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 energy storage cell 211 and the second energy storage cell 221. The communication portion 49 may be provided in either the first wall portion 41 or the second wall portion 42.

[0102] Even when configured as described above, energy storage device 10A according to the first modification can achieve substantially the same effects as energy storage device 10 according to embodiment 1. Furthermore, when cross member 40 according to the first modification is employed, if there is not a sufficient gap between upper wall portion 43 of cross member 40 and upper member 31, gas can be effectively discharged toward the space located above first energy storage cell 211 and second energy storage cell 221.

[0103] (Second Modification) 8 is a cross-sectional view showing a cross member and its surrounding structure according to the second modified example. Referring to FIG. 8, an electricity storage device 10B according to the second modified example will be described.

[0104] 8, energy storage device 10B according to the second modification differs from energy storage device 10 according to embodiment 1 in the positions of first opening 47 and second opening 48 provided in cross member 40, and the positions of first exhaust valve 216 and second exhaust valve 226. The other configurations are substantially the same.

[0105] In the second modified example, the first opening 47 and the second opening 48 are arranged to overlap when viewed from the first direction. The first exhaust valve 216 and the second exhaust valve 226 are also arranged to overlap when viewed from the first direction. The first exhaust valve 216 is provided, for example, in the center of the first side wall portion 213 in the vertical direction. The second exhaust valve 226 is provided, for example, in the center of the second side wall portion 223 in the vertical direction.

[0106] Even when configured as described above, the energy storage device 10B according to the second modification can achieve substantially the same effects as the energy storage device 10 according to embodiment 1. In the second modification, when a discharged object is introduced into the inside of the cross member 40 through one of the first opening 47 and the second opening 48, the discharged object heads directly toward the other of the first opening 47 and the second opening 48, but the momentum of the discharged object is suppressed by the heat insulating member 60 provided in one opening and the heat insulating member 60 provided in the other opening. This makes it possible to suppress the effect of heat on the energy storage cells located on the other opening side.

[0107] (Embodiment 2) 9 is an exploded perspective view of a power storage device according to Embodiment 2. With reference to FIG. 9, a power storage device 10C according to Embodiment 2 will be described.

[0108] 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.

[0109] In the second embodiment, when power storage device 10C is mounted on vehicle body 2, the first direction is parallel to the width direction of vehicle 1, and the second direction is parallel to the front-rear direction of vehicle 1.

[0110] The plurality of power storage modules 20 are arranged in a matrix in the first and second directions. 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.

[0111] 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.

[0112] The partition walls 50 divide 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 a first direction. The partition walls 50 may have a hollow structure.

[0113] An exhaust unit 80 is provided on the upper member 31 of the accommodating case 30. The exhaust unit 80 exhausts gas inside the accommodating case 30 when the internal pressure inside the accommodating case 30 exceeds a predetermined pressure. Specifically, when gas contained in the exhaust material is exhausted from the power storage cells included in the plurality of power storage modules 20 into the accommodating case 30 and the internal pressure inside the accommodating case 30 exceeds a predetermined pressure, the exhaust unit 80 exhausts the gas to the outside of the accommodating case 30.

[0114] Fig. 10 is a plan view showing the inside of the energy storage device according to embodiment 2. As shown in Fig. 10, 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 module 21 and a third energy storage module 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 module 22 and a fourth energy storage module 24.

[0115] In the power storage modules 20 located on one side in the first direction, the first power storage module 21 and the third power storage module 23 are arranged facing each other in the first direction.

[0116] The first energy storage module 21 has a plurality of first energy storage cells 211. The plurality of first energy storage cells 211 are arranged in the second direction. The first energy storage cell 211 has a pair of sidewalls in the first direction, and a pair of external terminals having different curves is provided on the first sidewall 213 located on the side closest to the cross member 40. Of the pair of sidewalls, the sidewall located opposite the first sidewall 213 is in thermal contact with a cooler 70, which will be described later.

[0117] The third power storage module 23 is arranged with respect to the first power storage module 21 on the opposite side to the side on which the above-mentioned second power storage module 22 is located. The third power storage module 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 with respect to the first power storage cells 211 on the opposite side to the side on which the above-mentioned second power storage cells 221 included in the second power storage module 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 a pair of external terminals having opposite polarities are provided on the sidewall portion.

[0118] In the power storage module 20 located on the other side in the first direction, the second power storage module 22 and the fourth power storage module 24 are arranged opposite each other in the first direction.

[0119] The second energy storage module 22 has a plurality of second energy storage cells 221. The plurality of second energy storage cells 221 are arranged in the second direction. The second energy storage cell 221 has a pair of sidewalls in the first direction, and a pair of external terminals having different curves is provided on the second sidewall 223 located closest to the cross member 40. Of the pair of sidewalls, the sidewall located opposite the second sidewall 223 is in thermal contact with a cooler 70, which will be described later.

[0120] The fourth power storage module 24 is arranged with respect to the second power storage module 22 on the opposite side to the side on which the above-mentioned first power storage module 21 is located. The fourth power storage module 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 module 21 are located. The fourth power storage cell 241 includes a side wall portion on the side opposite to the side on which the second power storage cells 221 are located, and a pair of external terminals having opposite polarities are provided on the side wall portion.

[0121] 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 cylindrical shape that is flattened in the second direction.

[0122] 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 modules adjacent to each other in the second direction in each energy storage module 20 so as to cool both of the energy storage modules 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 module 21 and the third energy storage module 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 module 22 and the fourth energy storage module 24. The cooler 70 has a refrigerant flow path therein through which a cooling medium flows.

[0123] The cross member 40 has a first end and a second end at both ends in the second direction, and the communication portion 49 extends continuously from the first end toward the second end.

[0124] 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) may be equal to or greater than the length in the second direction from one of first exhaust valves 216 included in each of the multiple 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.

[0125] The cross member 40 in the second embodiment can also be the cross member 40 in any one of the first embodiment, the first modified example, and the second modified example. As a result, the power storage device 10C in the second embodiment can also achieve substantially the same effects as the power storage device in the first embodiment, the first modified example, or the second modified example.

[0126] 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.

[0127] 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.

[0128] (Other variations) In the above-described first and second embodiments and the first and second modified examples, the case where the first exhaust valve 216 faces the first opening 47 and the second exhaust valve 226 faces the second opening 48 has been described as an example, but the present invention is not limited to this. The first exhaust valve 216 does not have to face the first opening 47 as long as it faces the first side wall portion 213, and the second exhaust valve 226 does not have to face the second opening 48 as long as it faces the second side wall portion 223.

[0129] Even in this case, when exhaust is discharged from one of the first exhaust valve 216 and the second exhaust valve 226, the exhaust can be introduced into the inside of the cross member 40 from the opening of the first opening or the second opening that is closer to the one exhaust valve. This allows the exhaust to be collected inside the cross member 40.

[0130] In the above-mentioned first and second embodiments, the first modified example, and the second modified example, an example has been described in which the insulating member 60 is provided in the first opening 47 and the second opening 48, but this is not limited to this, and the insulating member 60 may be omitted.

[0131] In the above-described first and second embodiments and the first and second modified examples, the cross member 45 has the bottom wall portion 44, but this is not limiting, and the bottom wall portion 44 may be omitted. In this case, flange portions may be provided so as to extend outward from the lower ends of the first wall portion 41 and the second wall portion 42, and the flange portions may be fixed to the bottom wall portion 321 of the storage case 30. In this case, a portion of the bottom wall portion 321 of the storage 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.

[0132] In the above-described first and second embodiments, the first modified example, and the second modified example, the communication portion 49 is exemplified as being provided above the upper wall portion 43 or the first storage cell 211 and the second storage cell 222, but the communication portion 49 may also be provided above the first exhaust valve 216 and the second exhaust valve 226.

[0133] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0134] 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 energy storage device, 10a upper surface, 20 energy storage module, 21 first energy storage module, 22 second energy storage module, 23 third energy storage module, 24 fourth energy storage module, 25 electrode body, 30 housing case, 31 upper member, 32 lower member, 35 main body portion, 36 fixed portion, 40 cross member, 41 first wall portion, 42 second wall portion, 43 upper wall portion, 44 bottom wall portion, 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, first side wall portion, 213A, external terminal, 216, first exhaust valve, 221, second storage cell, 222, housing, 223, second side wall portion, 223A, 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 portions, H, hollow portion.

Claims

1. a first storage cell and a second storage cell arranged side by side at an interval in a first direction; a cross member extending along a second direction perpendicular to the first direction and disposed in a gap between the first storage cell and the second storage cell, the first storage cell has a first side wall portion facing the cross member, a first exhaust valve is provided on the first side wall portion, The cross member has a hollow portion in a cross section perpendicular to the second direction, and a first opening portion is provided opposite the first side wall portion, The cross member is provided with a communication portion that communicates the hollow portion with a space surrounding the cross member, The communication portion is provided at a position that does not face the first exhaust valve.

2. The power storage device according to claim 1 , wherein the first opening is disposed opposite the first exhaust valve.

3. the second storage cell has a second side wall portion facing the cross member, The second side wall portion is provided with a second exhaust valve, The power storage device according to claim 2 , wherein the cross member is provided with a second opening portion facing the second side wall portion.

4. The power storage device according to claim 3 , wherein the first opening and the second opening are covered with a breakable heat insulating member.

5. The power storage device according to claim 4 , wherein the heat insulating member is provided with an easily breakable portion.

6. 6. The energy storage device according to claim 3, wherein the first opening and the second opening are arranged to be offset in a vertical direction perpendicular to the first direction and the second direction when viewed from the first direction.

7. 6. The power storage device according to claim 1, wherein the communication portion is provided above the first exhaust valve in a vertical direction perpendicular to the first direction and the second direction.

8. a height of the cross member in the vertical direction is greater than a height of the first energy storage cell and a height of the second energy storage cell in the vertical direction; The power storage device according to claim 7 , wherein the communication portion is provided above the first power storage cell and the second power storage cell.

9. the cross member has an upper wall portion on an upper side in the vertical direction, The power storage device according to claim 7 , wherein the communication portion is provided in the upper wall portion.

10. a first energy storage module in which a plurality of the first energy storage cells are arranged in the second direction; a second energy storage module in which a plurality of the second energy storage cells are arranged in the second direction, the cross member is disposed between the first power storage module and the second power storage module, 6. The energy storage device according to claim 1, wherein a length of the communication portion in the second direction is equal to or greater than a length in the second direction from a first exhaust valve located on one side of the second direction among the first exhaust valves of each of the plurality of first energy storage cells to a first exhaust valve located on the other side of the second direction among the first exhaust valves.

11. a third storage cell disposed on an opposite side of the first storage cell to a side on which the second storage cell is located in the first direction; 6. The energy storage device according to claim 1, further comprising: a cooler disposed in a gap between the first energy storage cell and the third energy storage cell, the cooler cooling the first energy storage cell and the third energy storage cell.

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