Battery module

Abstract

Provided is a battery module that prevents an electrical short circuit between a battery cell and a restraining member and suppresses heat of an adjacent battery cell from affecting the other battery cell. The battery module is provided with a laminate in which a plurality of battery cells are laminated, and a constraining member that constrains the laminate, and is provided with a heat transfer material that is interposed between side surfaces of the battery cells and the constraining member and has insulating properties. The constraining member includes a first constraining portion in contact with the heat conduction member in contact with the first battery cell, and a second constraining portion disposed in parallel with the first constraining portion and in contact with the heat conduction member in contact with the second battery cell, and the first constraining portion and the second constraining portion are each in contact with the heat conduction member so as to skip at least one battery cell. The heat of one of the adjacent battery cells is not transferred to the other via the constraining member, and a gap or an insulating material having heat insulation properties is provided between the first battery cell and the second constraining portion and between the second battery cell and the first constraining portion so that the battery cells and the constraining member do not come into contact with each other.

Description

Technical Field

[0001] The present invention relates to a battery module. Background Art

[0002] Patent Document 1 discloses a technique for increasing the thermal resistance between adjacent battery cells to suppress heat transfer from the abnormally heated battery cell to adjacent battery cells when any battery cell in a battery module comprised of multiple stacked battery cells generates abnormal heat. In the configuration described in Patent Document 1, thermal transfer between the battery cells is controlled using a band member that connects a pair of end plates and holds the battery cells.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2018 / 025567 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, the structure described in Patent Document 1 is a structure in which the metal restraint member is in direct contact with the cell case of the battery cell. Therefore, there is a possibility that the cell case of the battery cell and the restraint member may short-circuit, thereby generating heat due to the short-circuit.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide a battery module capable of preventing an electrical short circuit between a battery cell and a restraint member while suppressing thermal effects of adjacent battery cells on the other battery cell.

[0009] Technical solutions to problems

[0010] The present invention relates to a battery module comprising: a stacked body obtained by stacking a plurality of battery cells and a plurality of heat insulating members in an alternating arrangement; and a restraining member for restraining the stacked body, the restraining member being arranged opposite to a side surface of the stacked body and extending along a stacking direction of the stacked body, wherein the battery module is characterized in that the battery module comprises a heat conducting member having insulating properties interposed between the side surface of the battery cell and the restraining member, the plurality of battery cells comprising a first battery cell and a second battery cell adjacent to each other, the restraining member comprising: a first restraining portion in contact with the heat conducting member in contact with the first battery cell; and a second restraining portion , arranged in parallel with the first restraint portion and in contact with the heat-conducting member in contact with the second battery cell, the first restraint portion and the second restraint portion respectively contact the heat-conducting member by skipping at least one of the battery cells, so that the heat of one of the adjacent first and second battery cells is not transferred to the other battery cell via the restraint member, and a gap of an amount that prevents the side surface of the battery cell from contacting the restraint member or an insulating member with heat insulation is provided between the side surface of the first battery cell and the second restraint portion, and between the side surface of the second battery cell and the first restraint portion.

[0011] Effects of the Invention

[0012] In the present invention, it is possible to prevent an electrical short circuit between a battery cell and a restraint member while suppressing the heat of an adjacent battery cell from affecting the other battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a diagram for explaining a battery module in an embodiment.

[0014] Figure 2 is a diagram schematically showing a battery module.

[0015] Figure 3 It is a diagram for explaining a heat conducting member and an insulating member.

[0016] Figure 4 This is a diagram for explaining the structure in which the restraining member and the heat conducting member are in contact.

[0017] Figure 5 This is a diagram for explaining how heat is transferred from a battery cell that generates heat.

[0018] Figure 6 This is a diagram for explaining a structure in which a slit is provided in a restraining member.

[0019] Figure 7 This is a diagram for explaining a structure in which a cross member provided on a lower case of a battery pack contacts a heat conducting member.

[0020] Figure 8 This is a diagram for explaining a structure in which three restraint members are arranged on one side surface of a battery cell.

[0021] Figure 9 This is a diagram for explaining a structure in which three restraint members are arranged on one side surface.

[0022] Description of Reference Numerals

[0023] 1: Battery module;

[0024] 2: Battery unit;

[0025] 2b: lateral view;

[0026] 2A: 1st battery cell;

[0027] 2B: 2nd battery cell;

[0028] 3: Thermal insulation;

[0029] 4: laminate;

[0030] 5: end plate;

[0031] 6: Heat conduction parts;

[0032] 6A: 1st heat conducting member;

[0033] 6B: second heat conducting member;

[0034] 7: Insulation parts;

[0035] 7A: First insulating member;

[0036] 7B: Second insulating member;

[0037] 8: Constraint belt (constraint component);

[0038] 8A: First restraint belt (first restraint portion);

[0039] 8B: Second restraint belt (second restraint portion);

[0040] 9: lower shell;

[0041] 10: Transverse member (restraint member). DETAILED DESCRIPTION

[0042] Hereinafter, a battery module in an embodiment of the present invention will be described in detail. However, the present invention is not limited to the embodiment described below.

[0043] like Figure 1As shown, the battery module 1 includes a stacked body 4 in which a plurality of battery cells 2 and a plurality of heat insulating materials 3 are alternately stacked, a pair of end plates 5 sandwiching the stacked body 4 from both sides in the stacking direction, a heat conducting material 6 having insulating properties, and an insulating material 7 having heat insulating properties. Figure 2 As shown, the battery module 1 includes a restraining band 8 that restrains the stack 4. In the battery module 1, the battery cells 2 are cooled from their lower surfaces 2a by a cooler 21. The cooler 21 cools the lower surfaces 2a of the battery cells 2 via a heat conducting member 22. The heat conducting member 22 is interposed between the lower surfaces 2a of the battery cells 2 and the cooler 21. The battery module 1 is housed within a lower housing 9. The battery module 1 is housed in the battery pack housing (pack housing). The pack housing includes a lower housing 9 that houses the battery module 1.

[0044] like Figure 1 As shown, in the stack 4, adjacent battery cells 2 are insulated by heat insulating members 3. A pair of end plates 5 are arranged at both ends of the stack 4 in the stacking direction. A heat insulating member is provided between the end plates 5 and the battery cells 2. Figure 2 As shown, the stacked structure 4 is constrained by restraint bands 8 while being compressed in the stacking direction by a compressive load applied from a pair of end plates 5. The restraint bands 8 are restraining members whose ends in the stacking direction are fixed to the pair of end plates 5. The end plates 5 and restraint bands 8 are integrally fastened by bolts.

[0045] like Figures 2 to 4 As shown, the restraining bands 8 are side bands arranged opposite the side surfaces of the stack 4 and extending along the stacking direction of the stack 4. The restraining bands 8 are provided on both sides of the battery module 1, facing the side surfaces of the stack 4. The restraining bands 8 face the side surfaces 2b of the battery cells 2. The heat conducting members 6 and the insulating members 7 are arranged in two stages, one above the other, on the side surfaces 2b of the battery cells 2. The heat conducting members 6 and the insulating members 7 are interposed between the side surfaces 2b of the battery cells 2 and the restraining bands 8. The restraining bands 8 form a heat dissipation path for dissipating heat from the battery cells 2.

[0046] The heat conducting member 6 is a flat plate-shaped member provided on the side surface 2b of the battery cell 2, and forms a heat path for transferring the heat of the battery cell 2 to the restraining band 8. The heat conducting member 6 is interposed between the side surface 2b of the battery cell 2 and the restraining band 8. Figure 4 As shown, the thermally conductive member 6 is in surface contact with the side surface 2b of the battery cell 2 and with the restraining band 8. The thermally conductive member 6 has a thermal conductivity sufficient to absorb heat generated by abnormal heating of the battery cell 2. For example, the thermally conductive member 6 has a thermal conductivity of 1 W / mk or greater and a resistance of 10 MΩ or greater.

[0047] The insulating member 7 is a flat plate-shaped member provided on the side surface 2b of the battery cell 2, and provides thermal insulation between the battery cell 2 and the restraining band 8. The insulating member 7 is interposed between the side surface 2b of the battery cell 2 and the restraining band 8. The insulating member 7 is made of a material with high thermal resistance, such as mica.

[0048] In this structured battery module 1, when a battery cell 2 emits smoke, adjacent battery cells 2 are prevented from emitting smoke. A heat dissipation path is provided to transfer heat from the smoking battery cell 2 to locations other than adjacent battery cells 2 without inducing other heat generation patterns. The battery module 1 is structured so that at least one battery cell 2 and restraining band 8 are in contact with the thermally conductive member 6, preventing heat from being transferred from adjacent battery cells 2 through the restraining band 8.

[0049] The plurality of battery cells 2 include a first battery cell 2A and a second battery cell 2B adjacent to the first battery cell 2A. The plurality of battery cells 2 include adjacent first and second battery cells 2A and 2B. The thermally conductive member 6 includes a first thermally conductive member 6A in contact with the first battery cell 2A and a second thermally conductive member 6B in contact with the second battery cell 2B. The insulating member 7 includes a first insulating member 7A in contact with the first battery cell 2A and a second insulating member 7B in contact with the second battery cell 2B. The restraining band 8 includes a first restraining band 8A and a second restraining band 8B.

[0050] The first heat-conducting member 6A and the first insulating member 7A are arranged in two upper and lower stages on the side surface 2b of the first battery cell 2A. The second heat-conducting member 6B and the second insulating member 7B are arranged in two upper and lower stages on the side surface 2b of the second battery cell 2B. The first restraining band 8A contacts the first heat-conducting member 6A and the second insulating member 7B. The first restraining band 8A contacts the first heat-conducting member 6A and the second insulating member 7B alternately in the stacking direction. The second restraining band 8B is arranged parallel to the first restraining band 8A and contacts the second heat-conducting member 6B and the first insulating member 7A. The second restraining band 8B contacts the second heat-conducting member 6B and the first insulating member 7A alternately in the stacking direction. In the restraining band 8, the first restraining band 8A is the first restraining portion, and the second restraining band 8B is the second restraining portion. In cases where the distinction between the first and second is not particularly important, the reference numerals A and B are omitted.

[0051] The first restraining band 8A forms a heat dissipation path for dissipating the heat of the first battery cell 2A to locations other than adjacent battery cells. Figure 5As shown, the first restraining band 8A forms a heat dissipation path so that heat transferred from the first battery cell 2A via the first heat conducting member 6A is not transferred to the adjacent second battery cell 2B. The second restraining band 8B forms a heat dissipation path that dissipates heat from the second battery cell 2B to locations other than adjacent battery cells. The second restraining band 8B forms a heat dissipation path so that heat transferred from the second heat conducting member 6B to the second battery cell 2B is not transferred to the adjacent first battery cell 2A.

[0052] The first restraining band 8A and the second restraining band 8B each contact the heat conducting member 6 while skipping at least one battery cell 2, so that the heat of one of the adjacent first battery cell 2A and second battery cell 2B is not transferred to the other battery cell 2 via the restraining band 8. Figure 5 As shown, insulating members 7 are provided in portions that are not intended to form a heat path from the battery cells 2 to the restraining bands 8. A portion without heat transfer members 6 is provided between the first restraining band 8A and the second battery cell 2B. A portion without heat transfer members 6 is provided between the second restraining band 8B and the first battery cell 2A. Insulating members 7 are provided in these portions without heat transfer members 6. Therefore, if any battery cell 2 emits smoke, the heat from the smoking battery cell 2 is prevented from being transferred to adjacent battery cells.

[0053] In the battery module 1, the stacked body 4 has a Figure 5 In the case of the structure shown in FIG, the other side of the stack 4 has Figure 5 The structure shown is a structure that is reversed upside down. Taking the first battery unit 2A as an example, Figure 4 As shown, on one side surface 2b of the first battery cell 2A, the first heat conducting member 6A is positioned at the upper level, and the first insulating member 7A is positioned at the lower level. In this case, on the other side surface 2b of the first battery cell 2A, the first insulating member 7A is positioned at the upper level, and the first heat conducting member 6A is positioned at the lower level. This arrangement also applies to the second battery cell 2B.

[0054] As described above, according to the embodiment, when any battery cell 2 in the battery module 1 generates abnormal heat, heat transfer from that battery cell 2 to adjacent battery cells 2 can be suppressed, and short circuits between the battery cell 2 and the restraining band 8 can be prevented. Thus, thermal cascades caused by multiple battery cells 2 can be suppressed.

[0055] Furthermore, the insulating member 7 is not necessarily required. For example, in the portion where the heat conducting member 6 is not provided, a gap sufficient to prevent the side surface 2b of the battery cell 2 from contacting the restraining band 8 may be provided. In the portion where the heat conducting member 6 is not provided, a gap sufficient to prevent the battery cell 2 from contacting the restraining band 8 or an insulating member 7 may be provided.

[0056] In addition, the restraint belt 8 is not limited to a structure consisting of two members including the first restraint belt 8A and the second restraint belt 8B. Figure 6 As shown, it is composed of one component. Figure 6 The illustrated restraint band 8 includes a first restraint portion 81, a second restraint portion 82, and a slit 83. The first restraint portion 81, like the first restraint band 8A, forms a heat dissipation path for dissipating heat from the first battery cell 2A. The second restraint portion 82, like the second restraint band 8B, forms a heat dissipation path for dissipating heat from the second battery cell 2B. The first and second restraint portions 81, 82 are positioned opposite the side surfaces of the stack 4 and extend in the stacking direction, transversely across all battery cells 2 in the stack 4. On one side surface of the stack 4, the first restraint portion 81 is positioned on the upper side of the stack 4, and the second restraint portion 82 is positioned on the lower side of the stack 4. The slit 83 extends in the stacking direction at the center portion in the height direction, separating the first and second restraint portions 81, 82 into two stages. The slit 83 extends transversely across the entire side surface of the stack 4. The gap 83 can prevent heat conduction from the first restraining portion 81 to the second restraining portion 82, and from the second restraining portion 82 to the first restraining portion 81. The restraining band 8 can be divided, or it can be configured with the gap 83. In other words, it is sufficient as long as the thermal mass is divided.

[0057] In addition, in the battery module 1, the restraining member for restraining the stack 4 is not limited to the restraining belt 8. The restraining member may also be the transverse member 10 of the lower shell 9. The lower shell 9 is provided with a transverse member 10 for dividing the storage chamber of the battery module 1. The transverse member 10 is integrated with the lower shell 9. Figure 7 As shown, the cross member 10 is positioned opposite the side surface 2b of the battery cell 2. In the battery module 1 of the modified example, the cross member 10 of the housing forms a heat dissipation path in place of the restraining band 8. The restraining member with which the heat conducting member 6 contacts is not limited to the restraining band 8. The heat dissipation path for dissipating heat from the battery cell 2 transferred from the heat conducting member 6 may also include members other than the restraining band 8. The cross member 10 functions as a restraining member for restraining the stack 4.

[0058] The transverse member 10 is positioned opposite the side surface of the stack 4 and extends in the stacking direction so as to transversely intersect all of the battery cells 2 in the stack 4. The transverse member 10 includes a first transverse portion 11 and a second transverse portion 12. A gap is provided between the first transverse portion 11 and the second transverse portion 12 in the height direction. On one side surface of the stack 4, the first transverse portion 11 is positioned on the upper side of the stack 4, and the second transverse portion 12 is positioned on the lower side of the stack 4. The gap extends in the stacking direction at the center portion in the height direction, separating the first transverse portion 11 and the second transverse portion 12 into two stages. The gap extends across the entire side surface of the stack 4. The gap prevents heat conduction from the first transverse portion 11 to the second transverse portion 12, and heat conduction from the second transverse portion 12 to the first transverse portion 11. In the cross member 10 , the first cross portion 11 is a first restraining portion, and the second cross portion 12 is a second restraining portion.

[0059] In addition, the arrangement pattern of the heat conducting member 6 is not particularly limited as long as the adjacent battery cells 2 do not come into contact with the same restraining band 8 at the same time. Figure 4 As shown in FIG. 1 , the heat conducting members 6 are arranged in different patterns on the side surfaces 2b of the battery cell 2. Figure 8 As shown, the restraint belt 8 is divided into three parts.

[0060] like Figure 8 、 Figure 9 As shown, in the battery module 1 of the modified example, the restraint bands 8 have a structure arranged in three vertical stages. The restraint bands 8 include a first restraint band 8A, a second restraint band 8B, and a third restraint band 8C. One heat conducting member 6 and two insulating members 7 are arranged in three vertical stages on one side surface 2b of the battery cell 2. The plurality of battery cells 2 include a third battery cell 2C. In this case, the first battery cell 2A is adjacent to the second battery cell 2B and adjacent to the third battery cell 2C. The second battery cell 2B is adjacent to the first battery cell 2A and adjacent to the third battery cell 2C. The third battery cell 2C is adjacent to the second battery cell 2B and adjacent to the first battery cell 2A. The third restraint band 8C forms a heat dissipation path for dissipating heat from the third battery cell 2C. A third heat conducting member 6C and a third insulating member 7C are provided on the side surface 2b of the third battery cell 2C. The third heat conducting member 6C and the third insulating member 7C are interposed between the side surface 2b of the third battery cell 2C and the third restraining band 8C. The third restraining band 8C is a third restraining portion.

[0061] Furthermore, a cooler 21 or a thermal member having the same effect as the cooler 21 may be provided on the lower surface of the stacked body 4. The cooler 21 or the thermal member may be disposed inside the lower case 9 or below the lower case 9.

Claims

1. A battery module comprising: A stacked body in which a plurality of battery cells and a plurality of heat insulators are alternately stacked; and a restraining member for restraining the stacked body, The restraining member is arranged opposite to the side surface of the stacked body and extends along the stacking direction of the stacked body. The battery module is characterized in that: The battery module includes an insulating heat conducting member interposed between the side surface of the battery cell and the restraining member. The plurality of battery cells include a first battery cell and a second battery cell that are adjacent to each other. The restraining member comprises: a first restraining portion in contact with the heat conducting member in contact with the first battery cell; and a second restraining portion arranged in parallel with the first restraining portion and in contact with the heat conducting member in contact with the second battery cell; The first restraining portion and the second restraining portion each contact the heat conducting member while skipping at least one of the battery cells, so that heat from one of the adjacent first and second battery cells is not transferred to the other battery cell via the restraining member. A gap or a heat-insulating insulating material is provided between the side surface of the first battery cell and the second restraint portion, and between the side surface of the second battery cell and the first restraint portion, to prevent the side surfaces of the battery cells from contacting the restraint member.

2. The battery module according to claim 1, wherein: The insulating member is provided between the side surface of the first battery cell and the second restraining portion, and between the side surface of the second battery cell and the first restraining portion. The insulating member is interposed between the side surface of the battery cell and the restraint member, The first restraining portion contacts the heat conducting member in contact with the first battery cell and the heat insulating member in contact with the second battery cell alternately in the stacking direction. The second restraining portion alternately contacts the heat conductive member in contact with the second battery cell and the heat insulating member in contact with the first battery cell in the stacking direction.

3. The battery module according to claim 2, characterized in that The heat conducting member has a thermal conductivity of 1 W / mk or greater and a resistance of 10 MΩ or greater.

4. The battery module according to claim 3, characterized in that The battery module includes a pair of end plates arranged at both ends of the stack in the stacking direction and sandwiching the stack from both sides in the stacking direction. The restraining members are belt members whose both end portions in the stacking direction are fixed to the pair of end plates.

5. The battery module according to claim 3, characterized in that: The stacked body is housed in the lower shell of the battery pack. The restraint member is a cross member integrated with the lower housing.

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