Power storage device

Abstract

To provide a power storage device capable of suppressing the occurrence of a short circuit caused by dew condensation on an upper cover.SOLUTION: The energy storage apparatus 10 includes at least one energy storage cell 100, an upper cover 220 arranged above the at least one energy storage cell 100, a cooler 300 arranged on an upper surface of the upper cover to cool the at least one energy storage cell, and a cover 400 arranged between the at least one energy storage cell and the upper cover to cover the at least one energy storage cell.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] For example, JP 2022-525014 A discloses a power battery pack including a plurality of cells and a housing device. A module top plate having a cooling structure is disposed on the top surface of the plurality of cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2022-525014 Summary of the Invention [Problem to be solved by the invention]

[0004] In the power battery pack described in JP 2022-525014 A, if condensation occurs on the module top plate, there is a concern that the water droplets may come into contact with the external terminals of the cells, causing a short circuit.

[0005] An object of the present disclosure is to provide an electricity storage device that can suppress the occurrence of short circuits caused by condensation on the upper cover. [Means for solving the problem]

[0006] A storage device according to one aspect of the present disclosure includes at least one storage cell, an upper cover arranged above the at least one storage cell, a cooler arranged on an upper surface of the upper cover and cooling the at least one storage cell, and a cover arranged between the at least one storage cell and the upper cover and covering the at least one storage cell. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an electricity storage device that can suppress the occurrence of short circuits caused by condensation on the upper cover. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram schematically illustrating a vehicle including a power storage device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view schematically showing the power storage device and a frame member. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 10 is a cross-sectional view showing a modified example of the cover. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present disclosure will be described with reference to the accompanying drawings, in which the same or corresponding elements are designated by the same reference numerals.

[0010] Fig. 1 is a diagram schematically illustrating a vehicle including a power storage device according to an embodiment of the present disclosure. Fig. 2 is a perspective view schematically illustrating the power storage device and a frame member. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 3.

[0011] 1, a vehicle 1 includes a vehicle body 2 and a power storage device 10. Examples of the vehicle 1 include a hybrid electric vehicle, a plug-in hybrid electric vehicle, and an electric vehicle (battery electric vehicle).

[0012] 1 and 2, the vehicle body 2 includes a frame member 20. The frame member 20 is disposed at the bottom of the vehicle body 2. The frame member 20 has a pair of first frames 21, a pair of second frames 22, a first cross frame 23, and a second cross frame 24.

[0013] The pair of first frames 21 face each other in a first direction. Each first frame 21 has a shape extending along a second direction that is perpendicular to both the first direction and the up-down direction. For example, the first direction may be a direction parallel to the front-to-rear direction of the vehicle 1, and the second direction may be a direction parallel to the left-to-right direction (width direction) of the vehicle 1.

[0014] The pair of second frames 22 face each other in the second direction. Each second frame 22 has a shape extending along the first direction. An end of each second frame 22 in the first direction is connected to the first frame 21. The pair of second frames 22, together with the pair of first frames 21, are formed in a substantially rectangular tubular shape that surrounds the power storage device 10.

[0015] The first cross frame 23 is disposed between the pair of first frames 21 and connects the pair of second frames 22 to each other.

[0016] The second cross frame 24 is disposed between the pair of first frames 21 and connects the pair of second frames 22. The second cross frame 24 is spaced apart from the first cross frame 23 in the first direction. Each of the first cross frame 23 and the second cross frame 24 constitutes, for example, a seat cross.

[0017] The power storage device 10 is attached to a frame member 20. As shown in Fig. 2, the power storage device 10 is disposed below the first cross frame 23 and the second cross frame 24. As shown in Figs. 1 to 4, the power storage device 10 includes four power storage stacks 11 to 14, a housing 200, a cooler 300, a cover 400, and an equipment unit 800. The number of power storage stacks is not limited to four.

[0018] Each of the power storage stacks 11 to 14 includes at least one power storage cell 100. In this embodiment, each of the power storage stacks 11 to 14 includes a plurality of (for example, 50) power storage cells 100 arranged side by side along a first direction. Each of the power storage stacks 11 to 14 is formed in the shape of a rectangular parallelepiped that is long in the first direction. As shown in FIG. 2, the four power storage stacks 11 to 14 are arranged side by side along a second direction.

[0019] 3, a pair of end plates 51 are provided on both sides of the plurality of storage cells 100 in the first direction to sandwich the plurality of storage cells 100 from both sides in the first direction. A monitoring unit (Smart Battery Management) 52 is arranged on the outside of each end plate 51 in the first direction.

[0020] As shown in FIG. 4, each storage cell 100 has an electrode assembly 110, a cell case 120, and a pair of external terminals .

[0021] The electrode assembly 110 may be formed as 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 as a laminate in which a positive electrode sheet and a negative electrode sheet are stacked with a separator interposed therebetween. The electrode assembly 110 is formed in a shape that is long in the second direction.

[0022] The cell case 120 houses the electrode assembly 110. The cell case 120 is formed in a rectangular parallelepiped shape. The cell case 120 is made of a metal such as aluminum. A safety valve SV is provided on the bottom surface 121 of the cell case 120. In FIG. 4, the discharge direction of gas that can be discharged from the safety valve SV is indicated by a two-dot chain line.

[0023] The pair of external terminals 130 are provided on side surfaces 122 of the cell casing 120 in a width direction that is perpendicular to both the thickness direction and the up-down direction of the cell casing 120. One of the pair of external terminals 130 protrudes in the width direction from one side surface 122 of the cell casing 120 in the width direction. The other of the pair of external terminals 130 protrudes in the width direction from the other side surface 122 of the cell casing 120 in the width direction. The width direction corresponds to the second direction.

[0024] The housing 200 houses at least one energy storage cell 100. In this embodiment, the housing 200 houses four energy storage stacks 11 to 14. As shown in FIG. 4 , the housing 200 has a lower case 210, an upper cover 220, a panel member 230, a space forming member 250, and a cross member 260.

[0025] The lower case 210 is open upward and has a bottom surface 212 and a peripheral wall 214.

[0026] The bottom surface 212 is located below each of the power storage stacks 11 to 14. The bottom surface 212 may be formed in a flat plate shape.

[0027] Peripheral wall 214 stands upright from the peripheral edge of bottom surface 212. Peripheral wall 214 has a shape that surrounds the lower part of each of power storage stacks 11-14.

[0028] The upper cover 220 is disposed above at least one energy storage cell 100. In this embodiment, the upper cover 220 is disposed above the four energy storage stacks 11 to 14. The upper cover 220 accommodates the four energy storage stacks 11 to 14 together with the lower case 210. Specifically, the upper cover 220 accommodates the four energy storage stacks 11 to 14 together with the lower case 210 in a sealed state. The peripheral edge of the upper cover 220 is connected to the peripheral edge of the lower case 210 by bolts or the like via a sealing member.

[0029] The upper cover 220 has a top portion 221 and four recesses 222 .

[0030] The top portion 221 is formed flat and overlaps the ends of the power storage stacks in the second direction in the up-down direction.

[0031] Each recess 222 is recessed downward from the top portion 221. Each recess 222 is formed flat. Each recess 222 is formed above the center of each energy storage stack 11 to 14 in the second direction. As shown in FIG. 4, the length of each recess 222 in the second direction is shorter than the length of the energy storage cell 100 in the second direction. Each recess 222 is in contact with the upper surface of the cell casing 120 via a thermally conductive adhesive 910.

[0032] The panel member 230 is provided below the lower case 210. The panel member 230 has a function of protecting the lower case 210. The panel member 230 may be formed in a flat plate shape. As shown in FIG. 4 , the peripheral edge of the panel member 230 is connected to the lower case 210 via a bracket 80.

[0033] The space forming member 250 forms a space S together with the bottom surface 212 of the lower case 210. The space forming member 250 is provided between the bottom surface 212 of the lower case 210 and at least one energy storage cell 100. Specifically, the space forming member 250 is provided between the bottom surface 212 and each of the energy storage stacks 11 to 14. That is, in this embodiment, four spaces S are formed inside the housing 200.

[0034] Each space S functions as a smoke exhaust path (hereinafter referred to as a "smoke exhaust path S"). The smoke exhaust path S is a path for discharging gas discharged from the safety valve SV to the outside of the housing 200. Each smoke exhaust path S is connected to a common space within the housing 200 at the end of the smoke exhaust path S in the first direction.

[0035] 4, the space forming member 250 has through holes h provided below the safety valves SV. When gas is discharged from the safety valves SV of the energy storage cells 100, the gas flows into the smoke exhaust path S through the through holes h. In this embodiment, the through holes h are provided in positions facing the respective safety valves SV.

[0036] As shown in FIG. 3, an explosion-proof valve 290 is provided in a portion of the peripheral wall 214 that faces the smoke exhaust path S in the first direction. The explosion-proof valve 290 is provided in the common space within the housing 200. The explosion-proof valve 290 releases pressure within the housing 200. The explosion-proof valve 290 opens when the pressure within the housing 200 reaches or exceeds a reference value. The explosion-proof valve 290 is configured as a check valve. As shown in FIG. 3, when gas is discharged from any of the energy storage cells 100, the gas spreads in the first direction through the smoke exhaust path S and is discharged to the outside of the housing 200 through the explosion-proof valve 290.

[0037] As shown in FIG. 4, the space forming member 250 has a base portion 251 and a support portion 252. The base portion 251 is connected to the bottom surface 212 of the lower case 210 by welding or the like. The base portion 251 is formed flat. The base portion 251 extends along the first direction.

[0038] The support portion 252 protrudes from the base portion 251. The support portion 252 supports the plurality of energy storage cells 100 in each energy storage stack. The support portion 252 supports the plurality of energy storage cells 100 via adhesive members 920.

[0039] The support portion 252 is provided with a mounting portion 253. As shown in Fig. 4, the mounting portion 253 is recessed downward from the support portion 252. A through-hole h is formed in the mounting portion 253 at a location facing the safety valve SV.

[0040] As shown in FIG. 4, a heat insulating plate 255 may be placed on the mounting portion 253. The heat insulating plate 255 is provided between each through hole h of the space forming member 250 and the safety valve SV of the energy storage cell 100. Each heat insulating plate 255 is made of, for example, mica, which is a natural inorganic mineral solidified by heat pressing. Each heat insulating plate 255 has a shape that covers the through hole h. A notch may be formed in each heat insulating plate 255 at a portion that overlaps the edge of the through hole h. The heat insulating plate 255 may be attached to the lower surface 121 of the cell casing 120 so as to cover the safety valve SV.

[0041] The cross member 260 is connected by welding or the like to a portion of the base 251 between a pair of adjacent power storage stacks. For example, FIG. 4 shows a cross member 260 connected to the base 251 provided in a portion between a plurality of first power storage cells 101 (see FIG. 4) included in the power storage stack 11 arranged outermost in the second direction and a plurality of second power storage cells 102 (see FIG. 4) included in the power storage stack 12 adjacent to the power storage stack 11. The cross member 260 extends along the first direction. The cross member 260 is connected to the peripheral wall 214. The cross member 260 may be connected to the pair of first frames 21 via brackets (not shown).

[0042] As shown in FIG. 4, the cross member 260 has a reinforcing portion 262 and a connecting bottom surface 264 .

[0043] The reinforcing portion 262 has a shape that is convex in a direction away from the base portion 251. The reinforcing portion 262 is disposed below the external terminals 130 of the energy storage cell 100. The reinforcing portion 262 overlaps in the up-down direction with both of a pair of external terminals 130 that face each other in the second direction.

[0044] The connecting bottom surface 264 extends outward in the second direction from the lower end of the reinforcing portion 262. The connecting bottom surface 264 is connected to the base portion 251 by welding or the like. The connecting bottom surface 264 is formed flat.

[0045] The cooler 300 cools at least one energy storage cell 100. As shown in FIGS. 3 and 4, the cooler 300 is disposed on the upper surface of the upper cover 220. The cooler 300 is in thermal contact with at least one energy storage cell 100 via the upper cover 220. In this embodiment, the cooler 300 cools each of the energy storage stacks 11 to 14 via the upper cover 220. A cooling medium (water, etc.) flows inside the cooler 300. Note that being in thermal contact also includes a case where the cooler 300 is in indirect contact with the energy storage cell 100 via a thermally conductive member (adhesive, fixing member, etc.).

[0046] 3 and 4, the cooler 300 forms at least a part of the floor 30 of the vehicle compartment. In addition to the cooler 300, the floor 30 of the vehicle compartment may include cushioning materials, carpets, etc., placed on the cooler 300. Note that the cushioning materials, carpets, etc. are not shown in FIG. 2.

[0047] The cover 400 is disposed between at least one energy storage cell 100 and the upper cover 220, and covers at least one energy storage cell 100. In this embodiment, the cover 400 covers each of the energy storage stacks 11 to 14. The cover 400 extends from one end to the other end of each of the energy storage stacks 11 to 14 in the first direction. The cover 400 covers the cell case 120 and the external terminal 130 from above. The cover 400 is made of an insulating material (synthetic resin, etc.).

[0048] As shown in FIG. 4, the cover 400 has an interposed portion 410 , an extended portion 420 , and an opposing portion 430 .

[0049] The intervening portion 410 is interposed between the recess 222 of the upper cover 220 and the upper surface of the cell casing 120. The intervening portion 410 is formed flat. A thermally conductive adhesive 910 is provided between the intervening portion 410 and the recess 222, and between the intervening portion 410 and the upper surface of the cell casing 120. Therefore, the cooler 300 is in thermal contact with the upper surface of the cell casing 120 via the recess 222, the intervening portion 410, and the thermally conductive adhesive 910. The thickness of the intervening portion 410 may be formed to be the same as or smaller than the thickness of the recess 222.

[0050] The extension portion 420 protrudes in the second direction from the interposition portion 410. The extension portion 420 is disposed below the top portion 221.

[0051] The facing portion 430 faces the external terminal 130 in the second direction. The facing portion 430 extends downward from the outer end of the extension portion 420 in the second direction.

[0052] The equipment unit 800 is disposed, for example, at an end in the first direction. In this embodiment, the equipment unit 800 is disposed on the rear part of the upper cover 220 in the front-rear direction of the vehicle 1. The equipment unit 800 has a junction box 812, an electricity supply unit 814, an electronic control unit 816, a unit cooler 824, and an equipment cover 830.

[0053] The junction box 812 is disposed above the upper cover 220. The junction box 812 houses a relay, a fuse, and the like.

[0054] 3, the cooler 300 has an interposed portion 318 interposed between the upper cover 220 and the junction box 812. The junction box 812 is cooled by the interposed portion 318.

[0055] The power supply unit 814 is disposed above the junction box 812. The power supply unit 814 is cooled by a unit cooler 824 disposed above the power supply unit 814.

[0056] The electronic control unit 816 is disposed above the junction box 812 .

[0057] The equipment cover 830 houses the junction box 812 , the power supply unit 814 , the electronic control unit 816 , and the unit cooler 824 .

[0058] In the energy storage device 10 described above, when gas is discharged downward from the safety valve SV due to a short circuit or the like in any of the energy storage cells 100, the gas destroys the heat insulating plate 255 and flows into the smoke exhaust path S through the through-holes h of the space forming member 250. This prevents the contents of the energy storage cells 100 (so-called debris) contained in the gas from adhering to the external terminals 130 of the energy storage cells 100, etc.

[0059] Then, the gas that has flowed into the smoke exhaust path S spreads in a first direction and is discharged from the housing 200 through the explosion-proof valve 290 as shown in Fig. 3. Here, each of the through-holes h provided at a position facing the safety valve SV of the other energy storage cells 100 different from the energy storage cell 100 that has discharged the gas is blocked by the heat insulating plate 255, and therefore the gas spreading through the smoke exhaust path S is prevented from coming into contact with the lower surface 121 of the other energy storage cells 100. Therefore, the energy storage cells 100 other than the energy storage cell 100 that has discharged the gas are prevented from being heated by the gas.

[0060] Furthermore, since this energy storage device 10 is provided with a cover 400 that covers the energy storage cells 100, even if condensation occurs on the inner surface of the upper cover 220, the condensation is prevented from coming into contact with the energy storage cells 100 and causing a short circuit.

[0061] 5, the cover 400 may have a connecting portion 440. The connecting portion connects a pair of extension portions 420 adjacent to each other in the second direction. The connecting portion 440 covers a pair of external terminals 130 adjacent to each other in the second direction. In this embodiment, the four power storage stacks 11 to 14 are covered by a single cover 400.

[0062] It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0063] [Aspect 1] at least one storage cell; an upper cover disposed above the at least one energy storage cell; a cooler disposed on an upper surface of the upper cover and configured to cool the at least one energy storage cell; a cover disposed between the at least one power storage cell and the upper cover, the cover covering the at least one power storage cell.

[0064] This energy storage device is provided with a cover that covers the energy storage cells, so that even if condensation occurs on the inner surface of the upper cover, the condensation is prevented from coming into contact with the energy storage cells and causing a short circuit.

[0065] [Aspect 2] The at least one storage cell is An electrode body; a cell case that accommodates the electrode assembly; an external terminal protruding from the cell case in a direction perpendicular to both the thickness direction and the up-down direction of the cell case, 2. The power storage device according to claim 1, wherein the cover covers the cell case and the external terminal from above.

[0066] In this embodiment, the vertical dimension of the storage cell is reduced, and condensed water is prevented from reaching the external terminals.

[0067] [Aspect 3] The power storage device of aspect 2, further comprising a thermally conductive adhesive provided between the cover and the upper cover, and between the cover and the upper surface of the cell case.

[0068] In this manner, the relative position of the cover with respect to the storage cells and the upper cover is effectively determined, and further, thermal contact between the cooler and the storage cells is effectively ensured.

[0069] [Aspect 4] Aspect 4. The power storage device according to any one of aspects 1 to 3, wherein the cover is made of an insulating material.

[0070] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present disclosure is defined by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0071] REFERENCE SIGNS LIST 1 vehicle, 2 vehicle body, 10 energy storage device, 11 to 14 energy storage stack, 20 frame member, 21 first frame, 22 second frame, 23 first cross frame, 24 second cross frame, 51 end plate, 52 monitoring unit, 100 energy storage cell, 101 first energy storage cell, 102 second energy storage cell, 110 electrode body, 120 cell case, 121 lower surface, 122 side surface, 130 external terminal, 200 housing, 210 lower case, 212 bottom surface, 214 peripheral wall, 220 upper cover, 221 top portion, 222 recess, 230 panel member, 250 space forming member, 251 base portion, 252 support portion, 253 mounting portion, 255 heat insulating plate, 260 cross member, 262 reinforcing portion, 264 connection bottom surface, 290 Explosion-proof valve, 300 cooler, 400 cover, 410 interposed portion, 420 extension portion, 430 opposing portion, 440 connecting portion, 800 equipment unit, 812 junction box, 814 power supply unit, 816 electronic control unit, 824 unit cooler, 830 equipment cover, 910 thermally conductive adhesive, 920 adhesive material, h through hole, S space (smoke exhaust route), SV safety valve.

Claims

1. at least one storage cell; an upper cover disposed above the at least one energy storage cell; a cooler disposed on an upper surface of the upper cover and configured to cool the at least one energy storage cell; a cover disposed between the at least one power storage cell and the upper cover, the cover covering the at least one power storage cell.

2. The at least one storage cell is An electrode body; a cell case that accommodates the electrode assembly; an external terminal protruding from the cell case in a direction perpendicular to both the thickness direction and the up-down direction of the cell case, The power storage device according to claim 1 , wherein the cover covers the cell case and the external terminals from above.

3. The power storage device according to claim 2 , further comprising a thermally conductive adhesive provided between the cover and the upper cover, and between the cover and the upper surface of the cell case.

4. The power storage device according to claim 1 , wherein the cover is made of an insulating material.

Images