Electricity storage device

Abstract

The power storage device includes a plurality of power storage units, a housing, and a plurality of heat conduction members. The housing includes a contact surface. The contact surface has a plurality of contact portions and a thermal resistance portion. The thermal resistance portion includes an intermediate portion that passes between a pair of contact portions adjacent to each other among the contact surfaces and extends in a second direction intersecting the first direction within the contact surfaces, a first connecting portion, and a second connecting portion. The first connection portion connects an odd number of intermediate portions arranged from one side to the other side in the first direction and an intermediate portion arranged next to the intermediate portion. The second connecting part connects the odd-numbered middle parts arranged from one side to the other side in the first direction with the middle part arranged before the middle part.

Description

Technical Field

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

[0002] Japanese Patent Application Laid-Open No. 2023-149291 discloses an energy storage device comprising multiple energy storage elements and an outer casing. The outer casing includes a bottom wall, a pair of side walls, and a wall portion integral with the bottom wall. The pair of side walls face each other in a direction perpendicular to both the arrangement direction of the multiple energy storage elements and the vertical direction. The wall portion is provided between a pair of adjacent energy storage elements. The wall portion is separate from each of the side walls.

[0003] Therefore, even if a certain energy storage element is overheated, heat transfer to the side wall via the wall portion adjacent to the energy storage element can be suppressed, thereby suppressing heat transfer to other energy storage elements via the side wall. Summary of the Invention

[0004] In the power storage device described in Japanese Patent Application Laid-Open No. 2023-149291, when a power storage element generates heat, the heat may be transferred to an adjacent power storage element via a portion (recess) between the wall portion and the side wall of the bottom wall.

[0005] An object of the present disclosure is to provide an electric storage device capable of suppressing heat transfer from one electric storage cell to an adjacent electric storage cell via a contact surface of a case.

[0006] According to one aspect of the present disclosure, a power storage device includes:

[0007] a plurality of power storage units arranged in a first direction;

[0008] a housing for accommodating the plurality of power storage units; and

[0009] a plurality of heat conducting members respectively disposed between the power storage units and the housing;

[0010] The housing includes a contact surface that contacts the power storage unit via the heat conduction member.

[0011] The contact surface has:

[0012] a plurality of contact portions respectively contacting the heat conducting members; and

[0013] a thermal resistance portion having a thermal resistance greater than that of the contact portion,

[0014] The thermal resistance portion includes:

[0015] an intermediate portion passing between a pair of the contact portions adjacent to each other in the contact surface and extending in a second direction intersecting the first direction within the contact surface;

[0016] a first connecting portion that connects the intermediate portion that is arranged at an odd number from one side toward the other side in the first direction to the intermediate portion that is arranged next to the intermediate portion; and

[0017] a second connecting portion that connects the middle portion that is arranged at an odd number from one side toward the other side in the first direction to the middle portion that is arranged immediately before the middle portion;

[0018] The first connecting portion is provided at a position offset from a central portion of the contact surface in the second direction to one side in the second direction, and connects the end portions on one side in the second direction of a pair of adjacent intermediate portions.

[0019] The second connecting portion is provided at a position offset from the center portion of the contact surface in the second direction toward the other side in the second direction, and connects the other side end portions in the second direction of a pair of adjacent intermediate portions.

[0020] According to the present disclosure, it is possible to provide a power storage device capable of suppressing heat transfer from one power storage cell to an adjacent power storage cell via a contact surface of a case. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0022] Figure 1 is a plan view schematically showing a power storage device according to one embodiment of the present disclosure;

[0023] Figure 2 is a plan view schematically showing the housing and the heat conducting member;

[0024] Figure 3 yes Figure 1 A cross-sectional view at line III-III in FIG.

[0025] Figure 4 yes Figure 1 A cross-sectional view at line IV-IV in FIG.

[0026] Figure 5 is a cross-sectional view schematically showing a modified example of a heat conducting member; and

[0027] Figure 6 It is a cross-sectional view schematically showing a modified example of the contact portion of the housing. DETAILED DESCRIPTION

[0028] The embodiments of the present disclosure will be described with reference to the accompanying drawings. In the drawings referred to below, the same or corresponding components are denoted by the same reference numerals.

[0029] Figure 1 This is a plan view schematically showing a power storage device according to one embodiment of the present disclosure. Figure 2 It is a plan view schematically showing the housing and the heat conducting member. Figure 3 yes Figure 1 Cross-sectional view at line III-III in FIG. Figure 4 yes Figure 1 Cross-sectional view at line IV-IV in FIG.

[0030] like Figures 1 to 4 As shown, the power storage device 1 includes a plurality of power storage cells 100 , a plurality of heat insulators 200 , a pair of end plates 300 , a case 400 , a heat conductive member 500 , and a cooler 600 .

[0031] The plurality of storage cells 100 are arranged in a row in the first direction. Each storage cell 100 includes a storage cell case 110 that houses an electrode assembly (not shown) and a pair of external terminals 120. Figure 1 and Figure 3 As shown, a pair of external terminals 120 are provided on the upper surface of the storage cell case 110. In the present embodiment, the storage cell 100 is formed of a so-called prismatic storage cell.

[0032] Each heat insulating material 200 is disposed between a pair of adjacent power storage cells 100 .

[0033] The pair of end plates 300 sandwich the plurality of power storage cells 100 from both sides in the first direction.

[0034] The housing 400 houses a plurality of power storage cells 100 , a plurality of heat insulators 200 , and a pair of end plates 300 . The housing 400 is open upward and has a bottom surface 410 and a peripheral wall 420 .

[0035] The bottom surface 410 is disposed below the plurality of power storage cells 100. The bottom surface 410 is formed in a rectangular shape and can be formed flat.

[0036] The peripheral wall 420 rises from the edge of the bottom surface 410. The peripheral wall 420 is formed in a square tube shape that surrounds the plurality of power storage cells 100.

[0037] The heat conducting member 500 is provided between each storage battery cell 100 and the housing 400. The heat conducting member 500 is made of a heat conductive adhesive or the like. The heat conducting member 500 is in contact with the bottom surface 410 of the housing 400 and the bottom surface of each storage battery cell 100. In other words, the bottom surface 410 constitutes a "contact surface" that contacts each storage battery cell 100 via the heat conducting member 500. Therefore, hereinafter, the bottom surface 410 will be referred to as the contact surface 410. In addition, one surface of the peripheral wall 420 may also constitute a contact surface. Figure 4 As shown, the portion of the lower surface of each power storage cell 100 that is not in contact with the heat conducting member 500 is separated from the bottom surface 410 .

[0038] The contact surface 410 includes a contact portion 412 and a thermal resistance portion 450 .

[0039] The contact portion 412 is a portion that contacts each power storage cell 100 via the heat conductive member 500 .

[0040] The thermal resistance portion 450 has a thermal resistance greater than that of the contact portion 412. Figure 2 As shown, the thermal resistor 450 is formed in a meandering shape (zigzag shape) while avoiding the heat conducting members 500. The thermal resistor 450 includes a plurality of intermediate portions 452, a plurality of first connecting portions 454, and a plurality of second connecting portions 456.

[0041] Each intermediate portion 452 passes between a pair of adjacent contact portions 412 on the contact surface 410 and extends in a second direction intersecting the first direction within the contact surface 410. In this embodiment, the second direction is orthogonal to the first direction.

[0042] like Figure 4 As shown, the heat insulating material 200 is arranged at a position facing the middle portion 452 and separated from the middle portion 452. Specifically, the heat insulating material 200 is arranged above the middle portion 452. The thickness of the heat insulating material 200 in the first direction is greater than the length of the middle portion 452 in the first direction.

[0043] Each first connecting portion 454 connects the middle portion 452 arranged at an odd number (e.g., the third) from one side to the other side in the first direction to the middle portion 452 arranged next to the middle portion 452 (e.g., the fourth). Each first connecting portion 454 is provided at the center portion CL of the contact surface 410 in the second direction (see Figure 2 ) is biased toward one side in the second direction ( Figure 2 Each first connecting portion 454 connects the end portions on one side in the second direction of a pair of adjacent intermediate portions 452 to each other.

[0044] Each second connecting portion 456 connects the middle portion 452 arranged at an odd number (e.g., the third) from one side to the other side in the first direction to the middle portion 452 arranged immediately before the middle portion 452 (e.g., the second). Each second connecting portion 456 is provided at a position offset from the center portion CL of the contact surface 410 in the second direction toward the other side in the second direction ( Figure 2 Each second connecting portion 456 connects the other end portions of a pair of adjacent intermediate portions 452 on the second direction to each other.

[0045] In this embodiment, the intermediate portion 452, the first connecting portion 454, and the second connecting portion 456 are formed by slits that penetrate the contact surface 410 in the thickness direction. However, the intermediate portion 452, the first connecting portion 454, and the second connecting portion 456 preferably have a thermal resistance greater than that of the contact portion 412. For example, they can be formed to be thinner than the thickness of the contact portion 412.

[0046] like Figure 2 As shown, each heat conducting member 500 is provided only between a pair of adjacent intermediate portions 452 and between the first straight line L1 and the second straight line L2. The first straight line L1 is a virtual straight line formed by connecting the plurality of first connecting portions 454. The second straight line L2 is a virtual straight line formed by connecting the plurality of second connecting portions 456.

[0047] The cooler 600 is arranged so as to be in thermal contact with the contact surface (the lower surface in this embodiment) of the housing 400 .

[0048] A case where a sudden increase in heat is generated in a certain storage cell 100 in the storage device 1 described above will be described. Figure 4 The following describes the case where the second storage unit from the left (hereinafter referred to as "heating storage unit") generates heat. Figure 4 The thickness of each arrow shown indicates the amount of heat transferred.

[0049] Although some of the heat generated in the heat-generating storage cell is transferred to the first adjacent storage cell (hereinafter referred to as the "first adjacent storage cell") as indicated by arrow AR11, the amount of heat transferred in the direction of arrow AR11 is reduced because thermal insulation material 200 is disposed between the heat-generating storage cell and the first adjacent storage cell. Similarly, as indicated by arrow AR12, the amount of heat transferred from the first adjacent storage cell to the second adjacent storage cell (hereinafter referred to as the "second adjacent storage cell") is further reduced.

[0050] On the other hand, a portion of the heat generated in the heat-generating power storage cell is transferred to the contact portion 412 via the heat conducting member 500 as indicated by arrow AR21. In this embodiment, the pair of contact portions 412 are separated by the intermediate portion 452, the first connecting portion 454, and the second connecting portion 456. Therefore, the heat transferred in the direction of arrow AR21 is prevented from being transferred to the first adjacent power storage cell via the contact portion 412.

[0051] Heat transferred from the heat-generating electricity storage cell to the contact portion 412 in the direction of arrow AR21 is transferred via the outer side of the second connecting portion 456 on the contact surface 410 of the housing 400 to the contact portion 412 located below the second adjacent electricity storage cell, as indicated by arrow AR22. Furthermore, the distance this heat travels is longer than the distance between a pair of adjacent contact portions 412, resulting in a smaller amount of heat transferred from the heat-generating electricity storage cell to the second adjacent electricity storage cell. Furthermore, the heat transferred to the contact portion 412 located below the second adjacent electricity storage cell is transferred to the second adjacent electricity storage cell via the heat conducting member 500, as indicated by arrow AR23.

[0052] As described above, in the power storage device 1 of the present embodiment, heat conduction from the heat-generating power storage cell to the first adjacent power storage cell via the contact surface 410 of the case 400 is suppressed.

[0053] Furthermore, each heat conducting member 500 is provided only at a position between a pair of adjacent intermediate portions 452 and between the first straight line L1 and the second straight line L2 .

[0054] In this scheme, if Figure 3 As shown, the distances from the thermally conductive member 500 to the external terminals 120 are substantially equal, and therefore the temperature distribution in each power storage cell 100 is substantially uniform.

[0055] Hereinafter, modifications of the above-described embodiment will be described.

[0056] First Modification

[0057] like Figure 5 As shown, each heat conducting member 500 may also have a central member 510 and an outer member 520 .

[0058] The central member 510 is disposed between the pair of adjacent intermediate portions 452. The central member 510 facing the first connecting portion 454 in the second direction can extend outside the second straight line L2 in the second direction. The central member 510 facing the second connecting portion 456 in the second direction can extend outside the first straight line L1 in the second direction.

[0059] The outer member 520 is provided outside the first connection portion 454 in the second direction or outside the second connection portion 456 in the second direction.

[0060] The length of the outer member 520 in the second direction may be smaller than the length of the central member 510 in the second direction.

[0061] In this scheme, each storage unit 100 can be effectively cooled by the cooler 600 during steady (stable, normal) conditions (when no rapid heat generation occurs in any storage unit 100). In addition, the first connecting portion 454 is provided at a position deviated from the central portion CL of the contact surface 410 in the second direction to one side in the second direction. Furthermore, the second connecting portion 456 is provided at a position deviated from the central portion CL of the contact surface 410 in the second direction to the other side in the second direction. Furthermore, the length of the outer member 520 in the second direction is smaller than the length of the central member 510 in the second direction. Therefore, as Figure 5 As shown by the arrows in , heat generated in the heat-generating power storage cell is suppressed from being transferred to the power storage cell 100 adjacent to the power storage cell 100 via the outer member 520 .

[0062] Second Modification

[0063] like Figure 6 As shown, the contact portion 412 may have a labyrinth structure capable of restricting the outflow of the gas exhausted from the power storage cell 100 to the outside of the housing 400 through the intermediate portion 452. Figure 6 In the illustrated example, the contact portion 412 includes a support surface 412 a , an opposing surface 412 b , a connecting surface 412 c , and a shielding surface 412 d .

[0064] The support surface 412a supports the heat conducting member 500. The opposing surface 412b is spaced apart from the support surface 412a. The connecting surface 412c connects the support surface 412a and the opposing surface 412b. The shielding surface 412d overlaps the intermediate portion 452 in the thickness direction of the contact surface 410. The shielding surface 412d extends between the support surface 412a and the opposing surface 412b in the contact portion 412 adjacent to the contact portion 412 including the shielding surface 412d.

[0065] Those skilled in the art will understand that the above-described exemplary embodiments and examples are specific examples of the following aspects.

[0066] Solution 1

[0067] A power storage device comprising:

[0068] a plurality of power storage units arranged in a first direction;

[0069] a housing for accommodating the plurality of power storage units; and

[0070] a plurality of heat conducting members respectively disposed between the power storage units and the housing;

[0071] The housing includes a contact surface that contacts the power storage unit via the heat conduction member.

[0072] The contact surface has:

[0073] a plurality of contact portions respectively contacting the heat conducting members; and

[0074] a thermal resistance portion having a thermal resistance greater than that of the contact portion,

[0075] The thermal resistance portion includes:

[0076] an intermediate portion passing between a pair of the contact portions adjacent to each other in the contact surface and extending in a second direction intersecting the first direction within the contact surface;

[0077] a first connecting portion that connects the intermediate portion that is arranged at an odd number from one side toward the other side in the first direction to the intermediate portion that is arranged next to the intermediate portion; and

[0078] a second connecting portion that connects the middle portion that is arranged at an odd number from one side toward the other side in the first direction to the middle portion that is arranged immediately before the middle portion;

[0079] The first connecting portion is provided at a position offset from a central portion of the contact surface in the second direction to one side in the second direction, and connects the end portions on one side in the second direction of a pair of adjacent intermediate portions.

[0080] The second connecting portion is provided at a position offset from the center portion of the contact surface in the second direction toward the other side in the second direction, and connects the other side end portions in the second direction of a pair of adjacent intermediate portions.

[0081] In this power storage device, a pair of contact portions on the contact surface of the case are separated by the intermediate portion, the first connecting portion, and the second connecting portion. Therefore, even if heat is generated in one power storage cell, the heat can be prevented from being transferred to the adjacent power storage cell through the contact portions.

[0082] Meanwhile, heat generated in one storage cell is transferred to the second adjacent storage cell via the outer side of the first connecting portion or the outer side of the second connecting portion on the contact surface of the housing. However, the distance this heat travels is longer than the distance between a pair of adjacent contact portions, so the amount of heat transferred from one storage cell to the second adjacent storage cell is relatively small.

[0083] Option 2

[0084] According to the power storage device of claim 1,

[0085] The intermediate portion, the first connecting portion, and the second connecting portion are formed by slits that penetrate the contact surface in the thickness direction thereof.

[0086] In this aspect, heat insulation can be effectively performed at the intermediate portion, the first connecting portion, and the second connecting portion.

[0087] Option 3

[0088] The power storage device according to claim 1 or 2,

[0089] Each of the heat conducting members is provided only between a pair of adjacent intermediate portions and between a virtual first straight line formed by connecting the plurality of first connecting portions and a virtual second straight line formed by connecting the plurality of second connecting portions.

[0090] In this aspect, the temperature distribution in each power storage cell is substantially uniform.

[0091] Option 4

[0092] The power storage device according to claim 1 or 2,

[0093] The power storage device further includes a cooler arranged in thermal contact with the contact surface.

[0094] Each of the heat conducting members comprises:

[0095] a central member disposed between a pair of adjacent intermediate portions; and

[0096] an outer member provided on the outer side of the first connecting portion in the second direction or on the outer side of the second connecting portion in the second direction,

[0097] The length of the outer member in the second direction is smaller than the length of the central member in the second direction.

[0098] In this scheme, each storage unit can be effectively cooled by the cooler during steady (stable, normal) operation (when no sudden heat generation occurs in any storage unit). In addition, the first connecting portion is provided at a position deviated from the center of the contact surface in the second direction to one side in the second direction. Furthermore, the second connecting portion is provided at a position deviated from the center of the contact surface in the second direction to the other side in the second direction. Furthermore, the length of the outer member in the second direction is smaller than the length of the central member in the second direction. Therefore, even when sudden heat generation occurs in a storage unit, heat transfer to the storage unit adjacent to the storage unit via the outer member can be suppressed.

[0099] Option 5

[0100] According to the power storage device of claim 1,

[0101] The power storage device further includes a plurality of heat insulating materials each disposed between a pair of adjacent power storage cells.

[0102] In this aspect, heat transfer from one power storage cell to a power storage cell adjacent to the power storage cell can be more reliably suppressed.

[0103] Option 6

[0104] According to the power storage device of claim 5,

[0105] The heat insulating material is arranged at a position facing the middle portion and separated from the middle portion.

[0106] The embodiments disclosed herein are intended to be illustrative in all respects and not restrictive. The scope of the present disclosure is not indicated by the description of the embodiments described above but by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

Claims

1. A power storage device comprising: a plurality of power storage units arranged in a first direction; a housing for accommodating the plurality of power storage units; and a plurality of heat conducting members respectively disposed between the power storage units and the housing; The housing includes a contact surface that contacts the power storage unit via the heat conduction member. The contact surface has: a plurality of contact portions respectively contacting the heat conducting members; and a thermal resistance portion having a thermal resistance greater than that of the contact portion, The thermal resistance portion includes: an intermediate portion passing between a pair of the contact portions adjacent to each other in the contact surface and extending in a second direction intersecting the first direction within the contact surface; a first connecting portion that connects the intermediate portion that is arranged at an odd number from one side toward the other side in the first direction to the intermediate portion that is arranged next to the intermediate portion; and a second connecting portion that connects the middle portion that is arranged at an odd number from one side toward the other side in the first direction to the middle portion that is arranged immediately before the middle portion; The first connecting portion is provided at a position offset from a central portion of the contact surface in the second direction to one side in the second direction, and connects the end portions on one side in the second direction of a pair of adjacent intermediate portions. The second connecting portion is provided at a position offset from the center portion of the contact surface in the second direction toward the other side in the second direction, and connects the other side end portions in the second direction of a pair of adjacent intermediate portions.

2. The power storage device according to claim 1, The intermediate portion, the first connecting portion, and the second connecting portion are formed by slits that penetrate the contact surface in the thickness direction thereof.

3. The power storage device according to claim 1, Each of the heat conducting members is provided only between a pair of adjacent intermediate portions and between a virtual first straight line formed by connecting the plurality of first connecting portions and a virtual second straight line formed by connecting the plurality of second connecting portions.

4. The power storage device according to claim 1, The power storage device further includes a cooler arranged in thermal contact with the contact surface. Each of the heat conducting members comprises: a central member disposed between a pair of adjacent intermediate portions; and an outer member provided on the outer side of the first connecting portion in the second direction or on the outer side of the second connecting portion in the second direction, The length of the outer member in the second direction is smaller than the length of the central member in the second direction.

5. The power storage device according to claim 1, The power storage device further includes a plurality of heat insulating members respectively arranged between a pair of adjacent power storage cells. The heat insulating material is arranged at a position facing the middle portion and separated from the middle portion.

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