Electricity storage device

Abstract

The invention provides a power storage device. A power storage device includes a plurality of power storage cells, a bottom wall, and a panel member. A safety valve is provided on the lower surface of each of the battery cells. The bottom wall includes an upper plate portion and a lower plate portion. The upper plate portion has at least two upper through-holes provided at positions facing the safety valves. The lower plate portion has at least one lower through-hole provided at a position facing the at least two upper through-holes. The length of the lower through-hole in one direction is longer than the length of each of the upper through-holes in one direction.

Description

Technical Field

[0001] This disclosure relates to energy storage devices. Background Technology

[0002] For example, Japanese Patent Application Publication No. 2023-126584 discloses a battery comprising multiple battery cells, a housing containing the multiple battery cells, and a protective member protecting the bottom portion of the housing. A release mechanism is provided on the bottom surface of each battery cell. A leakage structure is provided at the bottom of the housing. Waste from the battery cells discharged from the release mechanism flows through the leakage structure into a collection chamber formed between the bottom portion of the housing and the protective member.

[0003] In the battery described in Japanese Patent Application Publication No. 2023-126584, a portion of the gas contained in the discharge from one cell may flow to a cell adjacent to that cell without passing through a leakage structure. Summary of the Invention

[0004] This disclosure provides an energy storage device capable of suppressing the gas contained in the discharge from a single energy storage cell and the contact between the energy storage cell and an adjacent energy storage cell.

[0005] The energy storage device according to the first aspect of this disclosure includes:

[0006] Multiple battery cells are arranged in one direction;

[0007] The bottom wall is located below the aforementioned plurality of battery cells; and

[0008] The panel component is located below the aforementioned bottom wall, and together with the aforementioned bottom wall, defines the smoke exhaust path.

[0009] A safety valve is installed on the lower surface of each of the aforementioned battery cells.

[0010] The aforementioned bottom wall includes:

[0011] The upper plate is located below the aforementioned multiple battery cells; and

[0012] The lower plate is located below the aforementioned upper plate.

[0013] The aforementioned upper plate has at least two through holes located opposite each of the aforementioned safety valves.

[0014] The lower plate portion has at least one lower through hole located opposite to the at least two upper through holes.

[0015] The length of the lower through hole in the aforementioned direction is longer than the length of each of the upper through holes in the aforementioned direction.

[0016] In the energy storage device according to the first aspect of this disclosure,

[0017] The aforementioned at least one of the aforementioned lower through holes may be disposed at a position that overlaps at least a portion of each of the pair of aforementioned upper through holes that are adjacent to each other in the vertical direction.

[0018] In the energy storage device according to the first aspect of this disclosure,

[0019] The aforementioned at least one lower through hole may be constituted by a single through hole, the single through hole extending from a position overlapping with the safety valve of the energy storage cell disposed at one end of the aforementioned one direction to a position overlapping with the safety valve of the energy storage cell disposed at the other end of the aforementioned one direction.

[0020] In the energy storage device according to the first aspect of this disclosure,

[0021] It may also include protective components installed on the aforementioned bottom wall.

[0022] The aforementioned protective component includes a plurality of heat-insulating components configured to seal the at least two upper through holes respectively.

[0023] In the energy storage device according to the first aspect of this disclosure,

[0024] It may also include protective components installed on the aforementioned bottom wall.

[0025] The aforementioned protective component includes a plurality of cylindrical portions protruding toward the aforementioned panel component from each of the at least two upper through holes.

[0026] In the energy storage device according to the first aspect of this disclosure,

[0027] The lower end of the aforementioned protective component may be positioned above the aforementioned panel component and exit from the aforementioned panel component.

[0028] According to this disclosure, an energy storage device is provided that can suppress gases contained in the discharge from a single energy storage cell and the energy storage cell adjacent to the single energy storage cell. Attached Figure Description

[0029] The features, advantages, and technical and industrial importance of embodiments of the present invention will now be described with reference to the accompanying drawings, wherein the same reference numerals denote the same elements.

[0030] Figure 1 This is a schematic diagram of a vehicle equipped with an energy storage device according to one embodiment of the present disclosure.

[0031] Figure 2 It is a three-dimensional diagram that roughly represents an energy storage device.

[0032] Figure 3 It is a top view that roughly shows the state of the energy storage device with the top cover removed.

[0033] Figure 4 yes Figure 3 A cross-sectional view along line IV-IV.

[0034] Figure 5 It is a three-dimensional view that roughly represents the lower shell.

[0035] Figure 6 It is a cross-sectional view that roughly represents a deformed example of the bottom wall.

[0036] Figure 7 It is a cross-sectional view that roughly represents a modified example of the protective component.

[0037] Figure 8 It is a three-dimensional drawing that roughly represents a deformed example of the base wall.

[0038] Figure 9 It is a cross-sectional view that roughly represents a deformed example of the bottom wall. Detailed Implementation

[0039] Embodiments of this disclosure will be described with reference to the accompanying drawings. In the drawings referred to below, identical or equivalent components are labeled with the same reference numerals.

[0040] Figure 1 This is a schematic diagram of a vehicle equipped with an energy storage device according to one embodiment of the present disclosure. Figure 2 It is a three-dimensional diagram that roughly represents an energy storage device. Figure 3 It is a top view that roughly shows the state of the energy storage device with the top cover removed. Figure 4 yes Figure 3 A cross-sectional view at line IV-IV. Figure 5 It is a three-dimensional view that roughly represents the lower shell.

[0041] like Figure 1 As shown, vehicle 1 includes a vehicle body 2 and an energy storage device 10. Examples of vehicles 1 include hybrid electric vehicles, plug-in hybrid electric vehicles, and battery electric vehicles.

[0042] like Figure 1 and Figure 2 As shown, the vehicle body 2 includes a frame component 20. The frame component 20 is disposed at the bottom of the vehicle body 2. The frame component 20 is formed into a generally rectangular tube shape that surrounds the energy storage device 10.

[0043] The energy storage device 10 is mounted on the frame component 20. For example... Figures 1-4 As shown, the energy storage device 10 includes six energy storage stacks 11-16, a frame 200, equipment 300, an equipment cooler 350, and refrigerant piping 400. Furthermore, the number of energy storage stacks is not limited to six.

[0044] Each of the energy storage stacks 11-16 is formed as a cuboid with length DR1 in the first direction. For example... Figure 3 As shown, the six battery stacks 11-16 are arranged along a second direction DR2, which is orthogonal to both the first direction DR1 and the vertical direction. In this embodiment, the first direction DR1 corresponds to the front-rear direction of the vehicle, and the second direction DR2 corresponds to the left-right direction (width direction) of the vehicle. Each battery stack 11-16 includes at least one battery cell 100. In this embodiment, each battery stack 11-16 includes multiple battery cells 100 and multiple cooling plates 150.

[0045] Multiple battery cells 100 are arranged in a manner that follows the first direction DR1. For example... Figure 4 As shown, each battery cell 100 has an electrode body 112, a cell housing 114, and a pair of external terminals 116.

[0046] The electrode body 112 can be formed by winding a positive electrode sheet and a negative electrode sheet with a separator in between, or by stacking a positive electrode sheet and a negative electrode sheet with a separator in between. The electrode body 112 is formed in a shape that is longer in the second direction DR2.

[0047] The cell housing 114 houses the electrode body 112. The cell housing 114 is formed in a cuboid shape. The cell housing 114 is made of a metal such as aluminum. A safety valve SV is provided on the lower surface of the cell housing 114.

[0048] A pair of external terminals 116 are disposed on the upper surface of the cell housing 114. The pair of external terminals 116 are disposed at positions that are separated from each other in the width direction of the cell housing 114. The width direction of the cell housing 114 corresponds to the second direction DR2.

[0049] like Figure 4 As shown, each cooling plate 150 is disposed between a pair of adjacent battery cells 100 in the first direction DR1. Each cooling plate 150 is formed as a flat plate elongated in the second direction DR2. Each cooling plate 150 has a flow path for refrigerant to flow along the second direction DR2 (not shown).

[0050] The 200mm frame houses six battery packs (11-16). Figures 2-5 As shown, the frame 200 has a lower housing 210, an upper cover 220, and a panel component 230.

[0051] The lower housing 210 has an opening at the top. The lower housing 210 may be formed of a metal such as aluminum. The lower housing 210 has a bottom wall 212, a peripheral wall 214, and a pair of partition walls 216.

[0052] The bottom wall 212 is located below each of the battery stacks 11-16. The bottom wall 212 has an upper plate portion 212A and a lower plate portion 212B. For example... Figure 4 As shown, a space is provided between the upper plate portion 212A and the lower plate portion 212B. Therefore, the bottom wall 212 is hollow. Furthermore, Figure 5 Similarly, the bottom wall 212 can be formed by extrusion molding.

[0053] An upper plate portion 212A is disposed below each of the energy storage stacks 11-16. The upper plate portion 212A may be formed in the shape of a flat plate. The upper plate portion 212A has at least two upper through holes h1 disposed at positions opposite to each safety valve SV. The at least two upper through holes h1 are arranged at intervals in the first direction DR1. In this embodiment, the at least two upper through holes h1 include a plurality of upper through holes h1. Each upper through hole h1 is disposed at a position opposite to the safety valve SV. That is, the number of upper through holes h1 arranged along the first direction DR1 is the same as the number of energy storage cells 100 contained in each energy storage stack 11-16.

[0054] The lower plate portion 212B is disposed below the upper plate portion 212A. The lower plate portion 212B may be formed as a flat plate. The lower plate portion 212B has at least one lower through hole h2 disposed at a position opposite to at least two upper through holes h1. The at least one lower through hole h2 is disposed at a position that overlaps at least a portion of each of a pair of upper through holes h1 adjacent to each other along the first direction DR1 in the vertical direction. In this embodiment, the at least one lower through hole h2 includes a plurality of lower through holes h2. Figure 4 As shown, each lower through hole h2 overlaps with a pair of upper through holes h1 adjacent to DR1 along the first direction in the vertical direction.

[0055] The length L2 of the lower through hole h2 on the first direction DR1 is longer than the length L1 of each upper through hole h1 on the first direction DR1. In this embodiment, the length of a pair of upper through holes h1 that are adjacent to each other along the first direction DR1 from one end to the other on the first direction DR1 is equal to the length L2 of a single lower through hole h2 on the first direction DR1.

[0056] like Figure 4 As shown, a protective member 280 may be provided on the upper plate portion 212A. The protective member 280 has multiple heat insulation members 282 and retaining members 284.

[0057] Each heat insulation component 282 has a shape that seals the upper through hole h1. Each heat insulation component 282 has the function of protecting each battery cell 100 from the gas discharged from the safety valve SV. Each heat insulation component 282 is, for example, made of mica, which is formed by hot pressing a natural inorganic mineral.

[0058] The retaining member 284 holds a plurality of heat-insulating members 282 arranged along the first direction DR1. Each heat-insulating member 282 may be bonded to the lower surface of the retaining member 284. The retaining member 284 is made of, for example, polypropylene.

[0059] 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 battery stacks 11 to 16. The peripheral wall 214 may be hollow. The peripheral wall 214 has a front wall 214a and a pair of side walls 214b.

[0060] The front wall 214a is formed on one side of each of the energy storage stacks 11 to 16 in the first direction DR1. Figure 3 (Left side of the vehicle). The front wall 214a extends along the second direction DR2. In this embodiment, one side on the first direction DR1 corresponds to the front side in the longitudinal direction of the vehicle.

[0061] A pair of sidewalls 214b are spaced apart from each other in the second direction DR2. Each sidewall 214b extends along the first direction DR1. One end (front end) of each sidewall 214b in the first direction DR1 is connected to the front wall 214a.

[0062] A pair of partition walls 216 divides the space surrounded by the bottom wall 212 and the peripheral wall 214 into spaces for arranging each of the energy storage stacks 11-16 and other spaces. The pair of partition walls 216 are arranged separately from each other in the first direction DR1. Each partition wall 216 extends along the second direction DR2. Each partition wall 216 can be hollow. The pair of partition walls 216 has the function of constraining each of the energy storage stacks 11-16 from both sides in the first direction DR1. Figure 3 As shown, the partition wall 216 formed on one side (front side) of the first direction DR1 separates from each side wall 214b at its end in the second direction DR2. The partition wall 216 formed on the other side (rear side) of the first direction DR1 is connected to each side wall 214b at its end in the second direction DR2.

[0063] The upper cover 220 is positioned above each of the six battery stacks 11-16. The upper cover 220 houses the lower casing 210 and the six battery stacks 11-16 together. Specifically, the upper cover 220 houses the lower casing 210 and the six battery stacks 11-16 in a sealed manner. The periphery of the upper cover 220 is connected to the upper end of the peripheral wall 214 via bolts or the like through a sealing component.

[0064] The panel component 230 is disposed below the lower housing 210. The panel component 230 functions to protect the bottom wall 212 of the lower housing 210. The panel component 230 may be formed in the shape of a flat plate. The periphery of the panel component 230 is connected to the lower surface of the lower housing 210 through a sealing member.

[0065] like Figure 4 As shown, a space S is formed between the panel component 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 battery cell 100 to the outside of the frame 200.

[0066] like Figure 3 and Figure 4 As shown, 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 gas upward from the smoke exhaust path S. An explosion-proof valve 290 is provided at the downstream end of the smoke exhaust duct section 218. The explosion-proof valve 290 releases the pressure inside the frame 200. The explosion-proof valve 290 opens when the pressure inside the frame 200 reaches a reference value or higher. The explosion-proof valve 290 is composed of a check valve. Figure 4 As shown, when gas is discharged from any of the battery cells 100, the gas passes through the exhaust path S and expands along the first direction DR1, passes through the exhaust pipe section 218 and the explosion-proof valve 290 and is discharged outside the frame 200.

[0067] Equipment category 300 is housed within frame 200. For example... Figure 3 As shown, device type 300 is disposed on the other side of the lower housing 210 in the first direction DR1, that is, in the space formed between the partition wall 216 and the peripheral wall 214 formed on the other side (rear side) of the first direction DR1. Device type 300 may include a junction box. Device type 300 may include relays, control devices, etc.

[0068] Equipment cooler 350 cools equipment 300. For example... Figure 3 and Figure 4 As shown, the equipment cooler 350 is disposed between the bottom wall 212 and the equipment 300. A thermally conductive adhesive 900 may be disposed between the equipment cooler 350 and the bottom wall 212.

[0069] Refrigerant piping 400 is arranged within the frame 200. Refrigerant piping 400 is connected to each cooling plate 150 and the equipment cooler 350. For example... Figure 2 and Figure 3As shown, an inlet port 181 and an outlet port 182 are provided on the front wall 214a of the peripheral wall 214. 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 into each cooling plate 150 and the equipment cooler 350, and after cooling each battery cell 100 and the equipment 300, it flows out from the outlet port 182 through the refrigerant piping 400.

[0070] like Figure 3 As shown, the refrigerant piping 400 has an upstream piping 410 and a downstream piping 420.

[0071] The upstream end of the upstream piping 410 is connected to the inflow port 181. The downstream end of the upstream piping 410 is connected to one end of the equipment cooler 350 on the second direction DR2. The upstream piping 410 is arranged between the front wall 214a and the partition wall 216 formed on one side of the first direction DR1, and between the battery stack 11 disposed on one side of the second direction DR2 and the side wall 214b. The upstream piping 410 is connected to one end of each cooling plate 150 on the second direction DR2.

[0072] The upstream end of the downstream piping 420 is connected to the other end of the equipment cooler 350 on the second direction DR2. The downstream end of the downstream piping 420 is connected to the outlet 182. The downstream piping 420 is arranged between the front wall 214a and the partition wall 216 formed on one side of the first direction DR1, and between the energy storage stack 16 disposed on the other side of the second direction DR2 and the side wall 214b. The downstream piping 420 is connected to the other end of each cooling plate 150 on the second direction DR2.

[0073] In the energy storage device 10 described above, such as Figure 4 As shown, if a short circuit or other event causes discharge material to be discharged downwards from the safety valve SV in any of the battery cells 100, the discharge material will collide with the protective component 280. As a result, the retaining component 284 will melt and the heat insulation component 282 will crack, causing the discharge material to flow into the smoke exhaust path S.

[0074] In this embodiment, since the length L2 of the lower through-hole h2 on the first direction DR1 is longer than the length L1 of each upper through-hole h1 on the first direction DR1, the pressure loss of the gas contained in the exhaust is reduced when it passes through the lower through-hole h2. Therefore, the gas flows into the exhaust path S effectively.

[0075] Subsequently, the gas contained in the exhaust extends through the exhaust path S, passes through the explosion-proof valve 290, and is discharged from the housing 200. Therefore, it can prevent the contents of the battery cell 100 (so-called debris) contained in the exhaust discharged from the battery cell 100 from adhering to the external terminals 116 of the battery cell 100, etc.

[0076] Hereinafter, variations of the above-described embodiments will be described.

[0077] Example 1

[0078] It can also be like Figure 6 As shown, the lower through hole h2 overlaps only with a single upper through hole h1 in the vertical direction. In this example, the length L2 of the lower through hole h2 in the first direction DR1 is also longer than the length L1 of each upper through hole h1 in the first direction DR1.

[0079] Second variation

[0080] It can also be like Figure 7 As shown, the energy storage device 10 also includes a protective member 280 disposed on the bottom wall 212. The protective member 280 includes a plurality of cylindrical portions 286. Each cylindrical portion 286 protrudes from the upper through hole h1 toward the panel member 230. The lower end of the cylindrical portion 286 exits the panel member 230 above the panel member 230. The protective member 280 is made of, for example, synthetic resin.

[0081] In this method, when the gas flowing into the exhaust path S through the cylinder 286 expands within the exhaust path S, such as Figure 7 As shown, the gas forms a swirling flow within a cylindrical portion 286 located below the battery cell 100 adjacent to the battery cell 100 that has discharged its waste. Therefore, it prevents the gas from rising within the cylindrical portion 286 and coming into contact with the safety valve SV of the adjacent battery cell 100.

[0082] 3rd variation

[0083] It can also be like Figure 8 and Figure 9 As shown, two upper through holes h1 are provided in the upper plate portion 212A, and a single lower through hole h2 is provided in the lower plate portion 212B. The lower through hole h2 is a single through hole that extends from a position in the vertical direction that overlaps with the safety valve SV of the battery cell 101 disposed on one end side of the first direction DR1, to a position in the vertical direction that overlaps with the safety valve SV of the battery cell 102 disposed on the other end side of the first direction DR1.

[0084] In this method, the pressure loss caused by the gas contained in the exhaust material discharged from a single battery cell 100 as it passes through the lower through-hole h2 can be further reduced. In addition, the bottom wall 212 can be made lighter.

[0085] For those skilled in the art, the embodiments illustrated above can be understood as specific examples of the following methods.

[0086] Method 1

[0087] An energy storage device, comprising:

[0088] Multiple battery cells are arranged in one direction;

[0089] The bottom wall is located below the aforementioned plurality of battery cells; and

[0090] The panel component is located below the aforementioned bottom wall, and together with the aforementioned bottom wall, defines the smoke exhaust path.

[0091] A safety valve is installed on the lower surface of each of the aforementioned battery cells.

[0092] The aforementioned bottom wall includes:

[0093] The upper plate is located below the aforementioned multiple battery cells; and

[0094] The lower plate is located below the aforementioned upper plate.

[0095] The aforementioned upper plate has at least two through holes located opposite each of the aforementioned safety valves.

[0096] The lower plate portion has at least one lower through hole disposed at a position opposite to the at least two upper through holes.

[0097] The length of the lower through hole in the aforementioned direction is longer than the length of each of the upper through holes in the aforementioned direction.

[0098] In this energy storage device, the pressure loss of the gas contained in the exhaust gas discharged from the battery cell as it passes through the lower through-hole is reduced, thus allowing the gas to flow effectively into the exhaust path. Therefore, contact between the gas contained in the exhaust gas discharged from one battery cell and an adjacent battery cell can be prevented.

[0099] Method 2

[0100] In the energy storage device described in Method 1,

[0101] The aforementioned at least one lower through hole is disposed at a position that overlaps at least a portion of each of the pair of aforementioned upper through holes that are adjacent to each other in the vertical direction.

[0102] Method 3

[0103] In the energy storage device described in Method 1,

[0104] The aforementioned at least one lower through hole is composed of a single through hole, which extends from a position overlapping with the safety valve of the energy storage cell disposed at one end in the aforementioned one direction to a position overlapping with the safety valve of the energy storage cell disposed at the other end in the aforementioned one direction.

[0105] In this method, gas flows into the exhaust path more efficiently, and the bottom wall can be made lighter.

[0106] Method 4

[0107] In the energy storage device described in method 1 or 2,

[0108] It also has protective components installed on the aforementioned bottom wall.

[0109] The aforementioned protective component includes a plurality of heat-insulating components configured to seal the at least two upper through holes respectively.

[0110] In this method, the gas contained in the discharge from one battery cell can be prevented from coming into contact with the safety valve of an adjacent battery cell.

[0111] Method 5

[0112] In the energy storage device described in method 1 or 2,

[0113] It also has protective components installed on the aforementioned bottom wall.

[0114] The aforementioned protective component includes a plurality of cylindrical portions protruding toward the aforementioned panel component from each of the at least two upper through holes.

[0115] In this method, the gas contained in the discharge from one battery cell can be prevented from coming into contact with the safety valve of an adjacent battery cell.

[0116] The embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. The scope of this disclosure is not shown by the description of the above embodiments, but by the technical solutions, and includes all modifications within the meaning and scope of equivalent technical solutions.

Claims

1. An energy storage device, characterized in that, have: Multiple battery cells are arranged in one direction; The bottom wall is located below the plurality of battery cells; as well as The panel component is located below the bottom wall and, together with the bottom wall, defines the smoke exhaust path. A safety valve is provided on the lower surface of each of the plurality of battery cells. The bottom wall comprises: The upper plate is disposed below the plurality of battery cells; and The lower plate is located below the upper plate. The upper plate has at least two through holes located opposite each of the safety valves. The lower plate portion has at least one lower through hole disposed at a position opposite to the at least two upper through holes. The length of the lower through hole in one direction is longer than the length of each of the upper through holes in the same direction.

2. The energy storage device according to claim 1, characterized in that, The at least one lower through hole is disposed at a position that overlaps at least a portion of each of the pair of upper through holes that are adjacent to each other in the vertical direction.

3. The energy storage device according to claim 1, characterized in that, The at least one lower through hole is formed by a single through hole, which extends from a position overlapping with the safety valve of the battery cell disposed at one end in the one direction to a position overlapping with the safety valve of the battery cell disposed at the other end in the one direction.

4. The energy storage device according to claim 1, characterized in that, It also has protective components installed on the bottom wall. The protective component includes a plurality of heat-insulating components configured to seal the at least two upper through holes respectively.

5. The energy storage device according to claim 1, characterized in that, It also has protective components installed on the bottom wall. The protective component comprises a plurality of cylindrical portions protruding toward the panel component from each of the at least two through holes.

6. The energy storage device according to claim 5, characterized in that, The lower end of the protective component exits the panel component above the panel component.

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