Energy storage device

Abstract

To provide an energy storage device that can suppress the scattering of contents of energy storage cells contained in the discharged waste from the energy storage cells. [Solution] The energy storage device 10 comprises at least one energy storage cell 100, a bottom wall 212, a panel member 230 provided below the bottom wall, and a protective member 280 provided on the bottom wall. A safety valve SV is provided on the lower surface of the energy storage cell. The bottom wall 212 has a through hole h provided at a position opposite the safety valve. The protective member 280 includes a heat insulating member 282 provided within the through hole. The heat insulating member 282 includes a receiving surface 282s located below the upper surface 212s of the bottom wall 212.

Description

Technical Field

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

Background Art

[0002] For example, Japanese Patent Translation Publication No. 2024-501935 discloses an electrical device including a plurality of battery cells, a first housing that houses the plurality of battery cells, a second housing that houses the first housing, and a separation member provided in the second housing. The separation member supports the first housing at a position above the bottom surface of the second housing. A collection cavity is formed below the separation member in the second housing. A third fragile region is provided on the lower surface of each battery cell, a pressure relief region is provided on the bottom surface of the first housing, and a second fragile region is provided on the separation member. Exhaust discharged from the battery cells through the third fragile region of the battery cells flows into a collection cavity formed below the separation member through the pressure relief region and the second fragile region.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the electrical device described in Japanese Patent Translation Publication No. 2024-501935, since it takes time for the exhaust discharged from the battery cells through the third fragile region to crack the pressure relief region and the second fragile region, there is a concern that some of the battery cell contents (so-called debris) contained in the exhaust will scatter into the space between the battery cells and the first housing without passing through the pressure relief region and the second fragile region.

[0005] An object of the present disclosure is to provide a power storage device capable of suppressing the scattering of the power storage cell contents contained in the exhaust of the power storage cell. [Means for solving the problem]

[0006] A power storage device according to one aspect of the present disclosure comprises at least one power storage cell, a bottom wall located below the at least one power storage cell, a panel member located below the bottom wall and together with the bottom wall defining a smoke exhaust path, and a protective member provided on the bottom wall, wherein a safety valve is provided on the lower surface of the at least one power storage cell, the bottom wall has a through hole located opposite the safety valve, the protective member includes a heat insulating member provided in the through hole, and the heat insulating member includes a receiving surface located below the upper surface of the bottom wall. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide an energy storage device that can suppress the scattering of contents of energy storage cells contained in the emissions of energy storage cells. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic perspective view of an energy storage device in one embodiment of the present disclosure. [Figure 2] This is a schematic plan view showing the power storage device with the upper cover removed. [Figure 3] This is a cross-sectional view taken along line III-III in Figure 2. [Figure 4] This is a schematic cross-sectional view showing a modified example of the protective member. [Figure 5] This is a schematic cross-sectional view showing modified examples of the bottom wall and protective member. [Figure 6] This is a schematic cross-sectional view showing modified examples of the bottom wall and protective member. [Figure 7] This is a schematic cross-sectional view showing a modified example of the protective member. [Modes for carrying out the invention]

[0009] Embodiments of this disclosure will be described with reference to the drawings. In the drawings referred to below, the same or equivalent components are given the same number.

[0010] Figure 1 is a schematic perspective view showing an energy storage device in one embodiment of the present disclosure. Figure 2 is a schematic plan view showing the energy storage device with the upper cover removed. Figure 3 is a cross-sectional view taken along line III-III in Figure 2.

[0011] In this embodiment, the energy storage device 10 is mounted, for example, on the underside of a vehicle. Examples of vehicles include hybrid electric vehicles, plug-in hybrid electric vehicles, and battery electric vehicles.

[0012] As shown in Figures 1 to 3, the energy storage device 10 comprises six energy storage stacks 11 to 16, a housing 200, a protective member 280, a surrounding member 290, equipment 300, an equipment cooler 350, and refrigerant piping 400. Note that the number of energy storage stacks is not limited to six.

[0013] Each energy storage stack 11-16 is formed in a rectangular parallelepiped shape that is elongated in the first direction DR1. As shown in Figure 2, the six energy storage stacks 11-16 are arranged to line up along a second direction DR2 that is perpendicular to both the first direction DR1 and the vertical direction. In this embodiment, the first direction DR1 corresponds to the longitudinal direction of the vehicle, and the second direction DR2 corresponds to the left-right direction (width direction) of the vehicle. Each energy storage stack 11-16 contains at least one energy storage cell 100. In this embodiment, each energy storage stack 11-16 contains a plurality of energy storage cells 100 and a plurality of cooling plates 150.

[0014] Multiple energy storage cells 100 are arranged in a line along a first direction DR1. As shown in Figure 3, each energy storage cell 100 has an electrode body 112, a cell case 114, and a pair of external terminals 116.

[0015] The electrode body 112 may be formed of a wound body in which a positive electrode sheet and a negative electrode sheet are wound with a separator interposed therebetween, or may be formed of a laminate in which a positive electrode sheet and a negative electrode sheet are laminated with a separator interposed therebetween. The electrode body 112 is formed in a shape that is long in the second direction DR2.

[0016] The cell case 114 houses the electrode body 112. The cell case 114 is formed in a rectangular parallelepiped shape. The cell case 114 is made of a metal such as aluminum. A safety valve SV is provided on the lower surface of the cell case 114.

[0017] A pair of external terminals 116 are provided on the outer surface of the cell case 114. In the present embodiment, the pair of external terminals 116 are provided on the upper surface of the cell case 114. The pair of external terminals 116 are provided at positions spaced apart from each other in the width direction of the cell case 114. Note that the width direction of the cell case 114 corresponds to the second direction DR2.

[0018] As shown in FIG. 3, each cooling plate 150 is disposed between a pair of power storage cells 100 adjacent to each other in the first direction DR1. Each cooling plate 150 is formed in a flat plate shape that is long in the second direction DR2. Each cooling plate 150 has a flow path (not shown) through which a refrigerant flows along the second direction DR2.

[0019] The housing 200 houses six power storage stacks 11 to 16. As shown in FIGS. 1 to 3, the housing 200 includes a lower case 210, an upper cover 220, and a panel member 230. ​​​​​​The bottom wall 212 is located below each of the energy storage stacks 11-16. In this embodiment, the bottom wall 212 is formed in a solid and flat shape. However, the bottom wall 212 may be formed in a hollow shape. The bottom wall 212 may be formed by extrusion molding. As shown in Figure 3, the bottom wall 212 has a plurality of through holes h. Each through hole h is located opposite the safety valve SV. The length of each through hole h in the first direction DR1 is greater than the length of the safety valve SV in the first direction DR1.

[0022] The protective member 280 is provided on the bottom wall 212. As shown in Figure 3, the protective member 280 has a plurality of heat insulating members 282 and a retaining sheet 284.

[0023] Each insulating member 282 is provided within the through-hole h. Each insulating member 282 includes a receiving surface 282s located below the upper surface 212s of the bottom wall 212. Each insulating member 282 has a shape that closes the through-hole h. In this embodiment, the lower surface of each insulating member 282 is set flush with the lower surface of the bottom wall 212. Each insulating member 282 has the function of protecting each energy storage cell 100 from gas discharged from the safety valve SV. Each insulating member 282 is made of, for example, mica, which is made by solidifying natural inorganic minerals by heat pressing.

[0024] The retaining sheet 284 holds a plurality of heat insulating members 282. The retaining sheet 284 is made of, for example, polypropylene. The retaining sheet 284 includes an adhesive portion 285 that is bonded to the receiving surface 282s below the upper surface 212s of the bottom wall 212. The back surface of the retaining sheet 284 may be bonded to the inner circumferential surface of the bottom wall 212 that surrounds the through hole h.

[0025] The surrounding member 290 is provided between the lower surface of the energy storage cell 100 and the upper surface 212s of the bottom wall 212. The surrounding member 290 has a shape that surrounds the through hole h. In this embodiment, the surrounding member 290 is provided between the bottom surface of the cell case 114 and the retaining sheet 284. The lower surface of the surrounding member 290 is in contact with the retaining sheet 284 located on the upper surface 212s of the bottom wall 212. The upper surface of the surrounding member 290 may be in contact with the bottom surface of the cell case 114. The surrounding member 290 is made of resin, metal, or the like. The surrounding member 290 may also be in contact with the underside of the cooling plate 150.

[0026] The peripheral wall 214 rises from the periphery of the bottom wall 212. The peripheral wall 214 has a shape that surrounds each of the energy storage stacks 11 to 16. The peripheral wall 214 may be formed in a hollow shape. The peripheral wall 214 has a front wall 214a and a pair of side walls 214b.

[0027] The front wall 214a is formed on one side (the left side in Figure 2) of each energy storage stack 11-16 in the first direction DR1. The front wall 214a extends in the second direction DR2. In this embodiment, one side in the first direction DR1 corresponds to the front side in the longitudinal direction of the vehicle.

[0028] A pair of side walls 214b are spaced apart from each other and face each other in the second direction DR2. Each side wall 214b extends in the first direction DR1. One end (front end) of each side wall 214b in the first direction DR1 is connected to the front wall 214a.

[0029] A pair of partition walls 216 divide the space enclosed by the bottom wall 212 and the perimeter wall 214 into a space in which each energy storage stack 11-16 is arranged and other spaces. The pair of partition walls 216 are spaced apart from each other in the first direction DR1. Each partition wall 216 extends in the second direction DR2. Each partition wall 216 may be formed in a hollow shape. The pair of partition walls 216 have the function of constraining each energy storage stack 11-16 from both sides in the first direction DR1. As shown in Figure 2, the end of the partition wall 216 formed on one side (front side) in the first direction DR1 in the second direction DR2 is spaced apart from each side wall 214b. The end of the partition wall 216 formed on the other side (rear side) in the first direction DR1 in the second direction DR2 is connected to each side wall 214b.

[0030] The upper cover 220 is positioned above each of the energy storage stacks 11-16. The upper cover 220, together with the lower case 210, houses the six energy storage stacks 11-16. Specifically, the upper cover 220, together with the lower case 210, houses the six energy storage stacks 11-16 in a sealed state. The peripheral edge of the upper cover 220 is connected to the upper end of the peripheral wall 214 by bolts or the like via a sealing member.

[0031] The panel member 230 is located below the lower case 210. The panel member 230 has the function of protecting the bottom wall 212 of the lower case 210. The panel member 230 may be formed in a flat plate shape. The peripheral edge of the panel member 230 is connected to the lower surface of the lower case 210 via a sealing member.

[0032] As shown in Figure 3, a space S is formed between the panel member 230 and the bottom wall 212. Each space S functions as a smoke exhaust path (hereinafter referred to as "smoke exhaust path S"). The smoke exhaust path S is a path for discharging the gas discharged from the safety valve SV of the energy storage cell 100 to the outside of the housing 200.

[0033] As shown in Figures 2 and 3, a smoke exhaust duct section 218 is formed in the peripheral wall 214. The smoke exhaust duct section 218 extends upward from the bottom wall 212. The smoke exhaust duct section 218 guides the gas upward from the smoke exhaust path S. An explosion-proof valve EV is provided at the downstream end of the smoke exhaust duct section 218. The explosion-proof valve EV releases the pressure inside the housing 200. The explosion-proof valve EV opens when the pressure inside the housing 200 exceeds a reference value. The explosion-proof valve EV is composed of a check valve. As shown in Figure 3, when gas is discharged from any of the energy storage cells 100, the gas spreads in the first direction DR1 through the smoke exhaust path S and is discharged outside the housing 200 through the smoke exhaust duct section 218 and the explosion-proof valve EV.

[0034] The equipment 300 is housed in the enclosure 200. As shown in Figure 2, the equipment 300 is located in the space formed between the partition wall 216 and the peripheral wall 214, which are located on the other side of the lower case 210 in the first direction DR1, i.e., on the other side (rear side) in the first direction DR1. The equipment 300 may include a junction box. The equipment 300 may include relays, control equipment, etc.

[0035] The equipment cooler 350 cools the equipment 300. As shown in Figures 2 and 3, the equipment cooler 350 is provided between the bottom wall 212 and the equipment 300. A thermally conductive adhesive 900 may be provided between the equipment cooler 350 and the bottom wall 212.

[0036] The refrigerant piping 400 is routed within the housing 200. The refrigerant piping 400 is connected to each cooling plate 150 and the equipment cooler 350. As shown in Figures 1 and 2, the front wall 214a of the peripheral wall 214 is provided with an inlet port 181 and an outlet port 182. The refrigerant piping 400 is connected to the inlet port 181 and the outlet port 182. Therefore, the refrigerant (water, oil, etc.) supplied from the inlet port 181 flows through the refrigerant piping 400 to each cooling plate 150 and the equipment cooler 350, cools each energy storage cell 100 and equipment 300, and then flows out through the refrigerant piping 400 from the outlet port 182.

[0037] As shown in Figure 2, the refrigerant piping 400 includes an upstream pipe 410 and a downstream pipe 420.

[0038] The upstream end of the upstream piping 410 is connected to the inlet port 181. The downstream end of the upstream piping 410 is connected to one end of the equipment cooler 350 in the second direction DR2. The upstream piping 410 is routed to pass between the front wall 214a and the partition wall 216 formed on one side in the first direction DR1, and between the energy storage stack 11 located on one side in the second direction DR2 and the side wall 214b. The upstream piping 410 is connected to one end of each cooling plate 150 in the second direction DR2.

[0039] The upstream end of the downstream pipe 420 is connected to the other end of the equipment cooler 350 in the second direction DR2. The downstream end of the downstream pipe 420 is connected to the outflow port 182. The downstream pipe 420 is routed to pass between the front wall 214a and the partition wall 216 formed on one side in the first direction DR1, and between the energy storage stack 16 located on the other side in the second direction DR2 and the side wall 214b. The downstream pipe 420 is connected to the other end of each cooling plate 150 in the second direction DR2.

[0040] In the energy storage device 10 described above, if a short circuit or the like causes discharge from the safety valve SV downward in any of the energy storage cells 100, the discharge flows into the through hole h and collides with the adhesive portion 285 and the receiving surface 282s. As a result, the adhesive portion 285 melts and the heat insulating member 282 ruptures, causing the discharge containing the contents of the energy storage cell 100 (so-called debris) to flow into the exhaust gas path S. Subsequently, the gas contained in the discharge spreads through the exhaust gas path S and is discharged from the housing 200 through the explosion-proof valve EV as shown in Figure 3.

[0041] Modifications of the above embodiment will be described below.

[0042] <First variation> As shown in Figure 4, the receiving surface 282s of the heat insulating member 282 may be formed in a shape that gradually slopes downward as it approaches the center in the first direction DR1.

[0043] <Second variation> As shown in Figure 5, the through hole h may have a reduced diameter portion h1 and a holding portion h2. The reduced diameter portion h1 gradually decreases in diameter from the upper surface 212s of the bottom wall 212 downwards. The holding portion h2 extends downwards from the lower end of the reduced diameter portion h1 and holds the heat insulating member 282.

[0044] In this embodiment, the contents of the energy storage cell 100 are more reliably allowed to flow into the through-hole h.

[0045] <Third variation> As shown in Figure 6, the bottom wall 212 may include a support portion 212b. The support portion 212b protrudes inward from the lower end of the inner circumferential surface of the bottom wall 212 that surrounds the through hole h. The support portion 212b supports the heat insulating member 282.

[0046] <Fourth variation> As shown in Figure 7, the retaining sheet 284 may be fixed to the lower surface of the bottom wall 212 by adhesive or other means. In this example, the heat insulating member 282 is supported from below by the retaining sheet 284.

[0047] <Fifth variation> Although not shown in the diagram, a pair of external terminals 116 may be provided on the lower surface of the cell case 114. In this case, a busbar (not shown) connecting the external terminals 116 of a pair of adjacent energy storage cells 100 is positioned between the energy storage cell 100 and the bottom wall 212. In this case, the surrounding member 290 is provided inside the pair of external terminals 116 and the busbar.

[0048] In this embodiment, the discharged material from the safety valve SV is prevented from adhering to the external terminal 116 or the busbar.

[0049] Those skilled in the art will understand that the exemplary embodiments described above are specific examples of the following embodiments.

[0050] [Aspect 1] At least one energy storage cell, A bottom wall positioned below at least one of the energy storage cells, A panel member provided below the bottom wall, which together with the bottom wall defines the smoke exhaust path, The bottom wall is provided with a protective member, A safety valve is provided on the lower surface of at least one of the energy storage cells. The bottom wall has a through hole located opposite the safety valve, The protective member includes a heat insulating member provided within the through hole. The energy storage device includes a receiving surface located below the upper surface of the bottom wall, wherein the heat insulating member is located below the upper surface of the bottom wall.

[0051] In this energy storage device, the insulating member provided within the through-hole has a receiving surface located below the upper surface of the bottom wall, so that the contents of the energy storage cells contained in the discharged material of the energy storage cells effectively flow into the through-hole. Therefore, the scattering of the contents of the energy storage cells is suppressed.

[0052] [Aspect 2] The protective member further includes a retaining sheet for holding the heat insulating member, The energy storage device according to embodiment 1, wherein the retaining sheet includes an adhesive portion that is adhered to the receiving surface below the upper surface of the bottom wall.

[0053] In this embodiment, the scattering of contents from the energy storage cell is suppressed, and the falling of the heat insulating material from the through-hole is also suppressed.

[0054] [Aspect 3] The aforementioned through hole is The bottom wall has a diameter reduction portion that gradually decreases in diameter as it extends downward from the upper surface, The energy storage device according to embodiment 1 or 2, comprising a holding portion that extends downward from the lower end of the reduced diameter portion and holds the heat insulating member.

[0055] In this embodiment, the contents of the energy storage cell are more reliably allowed to flow into the through-hole.

[0056] [Aspect 4] The energy storage device according to any one of embodiments 1 to 3, further comprising a surrounding member provided between the at least one energy storage cell and the bottom wall, and having a shape that surrounds the through hole.

[0057] In this embodiment, the contents of the energy storage cell are more reliably allowed to flow into the through-hole.

[0058] It should be noted that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of this disclosure is defined by the claims rather than the description of the embodiments above, and includes all modifications within the meaning and scope equivalent to the claims. [Explanation of symbols]

[0059] 1 Vehicle, 2 Vehicle body, 10 Energy storage device, 11-16 Energy storage stack, 100 Energy storage cell, 112 Electrode body, 114 Cell case, 116 External terminal, 200 Housing, 210 Lower case, 212 Bottom wall, 212s Top surface, 214 Peripheral wall, 216 Partition wall, 218 Smoke exhaust duct section, 220 Upper cover, 280 Protective member, 282 Insulation member, 282s Receiving surface, 284 Retaining sheet, 290 Enclosing member, 300 Equipment, 350 Equipment cooler, 400 Refrigerant piping, 410 Upstream piping, 420 Downstream piping, 900 Thermal conductive adhesive, EV Explosion-proof valve, h Through hole, h1 Reduced diameter section, h2 Retaining section, S Space (smoke exhaust path), SV Safety valve.

Claims

1. At least one energy storage cell, A bottom wall positioned below the at least one energy storage cell, A panel member provided below the bottom wall, which together with the bottom wall defines the smoke exhaust path, The bottom wall is provided with a protective member, A safety valve is provided on the lower surface of at least one of the energy storage cells. The bottom wall has a through hole located opposite the safety valve, The protective member includes a heat insulating member provided within the through hole. The energy storage device includes a receiving surface located below the upper surface of the bottom wall, wherein the heat insulating member is located below the upper surface of the bottom wall.

2. The protective member further includes a retaining sheet for holding the heat insulating member, The energy storage device according to claim 1, wherein the retaining sheet includes an adhesive portion that is adhered to the receiving surface below the upper surface of the bottom wall.

3. The aforementioned through hole is The bottom wall has a diameter reduction portion that gradually decreases in diameter as it extends downward from the upper surface, The energy storage device according to claim 1, further comprising a holding portion extending downward from the lower end of the reduced diameter portion and holding the heat insulating member.

4. The energy storage device according to any one of claims 1 to 3, further comprising a surrounding member provided between the at least one energy storage cell and the bottom wall, and having a shape that surrounds the through hole.

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