Battery module

Abstract

To improve a heat dissipation of a battery cell.SOLUTION: In a battery module 10, a plurality of battery cells 12 is laminated in a lamination direction, and a cooling device 24 is arranged on a lower side of each battery cell 12. In each battery cell 12, a metal plate 18 is arranged to both sides of the lamination direction, a heat insulation member 20 is arranged between the metal plates 18. Also, in each metal plate 18, an end part 18B of which a length in the lamination direction is longer than that of an intermediate part 18A in an upward view is formed. Each metal plate 18 is that a flat surface 28 of the end part 18B is contacted to the cooling device 24 on the surface. Therefore, in the battery module 10, a contact area between each metal plate 18 and the cooling device 24 is expanded, and heat of each metal plate 18 can be effectively radiated. Thus, in the battery module 10, heat radiation of the battery cell 12 can be improved by each metal plate 18.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a battery module.

Background Art

[0002] In the assembled battery described in Patent Document 1, a plurality of battery cells are stored inside a battery case, and a thermal control sheet (thermal control sheet for assembled battery) is interposed between adjacent battery cells. The thermal control sheet has an intermediate layer disposed between a pair of surface layers, and heat insulating materials are disposed between the intermediate layer and each of the surface layers. Materials having a lower emissivity and a higher thermal conductivity than the heat insulating material are used for the surface layer and the intermediate layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the thermal control sheet, if the heat of the surface layer or the intermediate layer is accumulated without being radiated, the surface layer may heat the intermediate layer, the heat insulating material, and the battery cell, and there is a concern that not only the battery cell that has generated heat but also the battery cell adjacent to this battery cell may be heated. Therefore, in a battery module using a plurality of battery cells, there is room for improvement in heat dissipation of the battery cells.

[0005] The present disclosure has been made in view of the above facts, and an object thereof is to provide a battery module with improved heat dissipation of battery cells.

Means for Solving the Problems

[0006] A battery module according to a first aspect for achieving the above object includes battery cells stacked in a first direction, metal plates disposed on both sides of each of the battery cells in the first direction, heat insulating members disposed between each of the battery cells and the metal plates and contacting each of the metal plates and the battery cells, and coolers disposed in a second direction intersecting the first direction with respect to each of the battery cells for cooling each of the battery cells. The metal plate includes a first portion in surface contact with the heat insulating member and a second portion at a second direction side end of the first portion. The second portion is formed such that a length in the first direction is longer than that of the first portion when viewed from the second direction and is in surface contact with the cooler.

[0007] In the first aspect, a plurality of battery cells are stacked in the first direction. Metal plates are disposed on both sides of each of the battery cells in the first direction, and heat insulating members are disposed between each of the battery cells and the metal plates. As a result, between battery cells adjacent in the first direction, heat insulating members, metal plates, and heat insulating members are sequentially disposed.

[0008] Further, the coolers are disposed in a second direction intersecting the first direction with respect to each of the battery cells, and each of the battery cells can be cooled by the coolers. For this reason, the heat insulating members can suppress the radiant heat emitted from the battery cells from being transmitted to the adjacent battery cells in the first direction, and heat can be transferred from the heat insulating members to the coolers via the metal plates.

[0009] Here, the metal plate includes a first portion in surface contact with the heat insulating member and a second portion at a second direction side end of the first portion. The second portion is formed such that a length in the first direction is longer than that of the first portion when viewed from the second direction and is in surface contact with the cooler.

[0010] As a result, compared to simply contacting the end face of the metal plate with the cooler, the contact area between the metal plate and the cooler can be widened and the heat dissipation property of the metal plate can be improved, so that the metal plate can effectively block the radiant heat emitted from the battery cells from being transmitted to the adjacent battery cells in the first direction.

[0011] In the battery module according to the second aspect, in the first aspect, end plates arranged in pairs on both sides in the first direction with the stacked battery cells interposed therebetween, and arranged on the side opposite to the cooler with respect to the battery cells in the second direction, and a metal connecting member connecting the end plates on both sides in the first direction are further provided, and in the metal plate, the second portion on the connecting member side is in surface contact with the connecting member.

[0012] In the battery module according to the second aspect, end plates are arranged in pairs on both sides in the first direction with the stacked battery cells interposed therebetween, and a connecting member is arranged on the side opposite to the cooler in the second direction with respect to the battery cells. The connecting member is made of metal and connects the end plates on both sides in the first direction. Further, in the metal plate, the second portion on the connecting member side is in surface contact with the connecting member.

[0013] As a result, the heat generated from the battery cells is transferred to the connecting member through the metal plate, and the heat can be dissipated from the connecting member. At this time, since the heat can be effectively transferred from the metal plate to the connecting member, the heat dissipation performance of the metal plate can be further improved.

Advantages of the Invention

[0014] According to the present disclosure, since the metal plate arranged between the battery cells adjacent in the first direction is connected to the cooler, the heat generated from the battery cells can be dissipated from the metal plate. At this time, since the second portion of the metal plate is connected to the cooler, the heat transfer area between the metal plate and the cooler can be increased, and thus the radiant heat generated from the battery cells can be effectively blocked from being transmitted to the battery cells adjacent in the first direction by the metal plate.

[0015] Further, in the present disclosure, a metal connecting member is provided, and the second portion of the metal plate is in contact with the connecting member. As a result, the heat can be effectively transferred from the metal plate to the connecting member, and thus the heat dissipation performance of the metal plate can be further improved.

Brief Description of the Drawings

[0016]

Figure 1

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In FIG. 1, the main part of the battery module 10 according to this embodiment is shown in a side view. In the drawing, the stacking direction as the first direction is indicated by an arrow X, and the vertical direction as the second direction, which is a direction intersecting the first direction, is indicated by an arrow Z. Further, in this embodiment, the direction intersecting each of the stacking direction (arrow X direction) and the vertical direction (arrow Z direction) is defined as the width direction, and the width direction corresponds to the front-back direction of the paper surface.

[0018] One or more of the battery modules 10 according to this embodiment are housed in a case (cell case) to form a battery pack as an assembled battery (both are not shown). The battery pack using the battery module 10 is mounted on, for example, a vehicle equipped with an electric motor (electric motor), and outputs electric power for driving the electric motor. Such a vehicle only needs to be equipped with an electric motor, and a hybrid vehicle (HEV: Hybrid Electric Vehicle), a plug-in hybrid vehicle (PHEV: Plug-in Hybrid Electric Vehicle), an electric vehicle (BEV: Battery Electric Vehicle), etc. can be applied.

[0019] As shown in FIG. 1, the battery module 10 includes a plurality of battery cells 12 and a pair of end plates 14. Each of the plurality of battery cells 12 has a substantially rectangular parallelepiped shape and is arranged in the stacking direction to form a battery stack 16.

[0020] A pair of end plates 14 are arranged, one on one side in the arrangement direction of the battery cells 12, and the other on the other side in the arrangement direction of the battery cells 12. As a result, in the battery module 10, a battery stack 16 in which a plurality of battery cells 12 are stacked is arranged between the pair of end plates 14. In the battery module 10, in the battery stack 16, a plurality of battery cells 12 are connected in series or in parallel so as to be able to output electric power of a predetermined voltage.

[0021] In addition, in FIG. 1, six battery cells 12 are shown as an example, but the number of battery cells 12 forming the battery module 10, that is, the battery stack 16, is not limited to this, and the number of battery cells 12 may be less than six or may be six or more.

[0022] Such battery cells 12 use secondary batteries such as lithium-ion batteries. Further, the battery cells 12 are not limited to lithium-ion batteries, and various secondary batteries such as all-solid-state batteries, lead batteries, nickel-cadmium batteries, and nickel-metal hydride batteries may be applied. Furthermore, the battery cells 12 are not limited to secondary batteries, and primary batteries (for example, manganese dry batteries, lithium graphite fluoride primary batteries, lithium manganese dioxide primary batteries, etc.) may be applied.

[0023] In the battery module 10, metal plates 18 are arranged as heat transfer parts and heat dissipation parts between the battery cells 12 adjacent in the stacking direction and between the battery cells 12 and the end plates 14. Further, heat insulating members 20 are arranged between the battery cells 12 and the metal plates 18 and between the end plates 14 and the metal plates 18, respectively. For this reason, in the battery module 10, the heat insulating members 20, the metal plates 18, and the heat insulating members 20 are stacked in this order in the stacking direction and are arranged between the battery cells 12 adjacent in the stacking direction and between the battery cells 12 and the end plates 14.

[0024] For the heat insulating member 20, a heat insulating material having conductivity may be used, but it is preferable to use a heat insulating material having insulating properties. In the battery module 10, a heat insulating material having insulating properties is used as the heat insulating member 20.

[0025] On the other hand, the battery module 10 includes a restraint band 22 as a connection member and a cooler 24 as a cooling unit. The restraint band 22 is spanned between a pair of end plates 14 above the battery cells 12, and both ends of the restraint band 22 in the arrangement direction of the battery cells 12 are connected to the upper end portions of the respective end plates 14.

[0026] This restraint band 22 is made of metal. The restraint band 22 is formed in a strip shape, for example, and both end portions in the longitudinal direction are fastened and fixed to the upper end portions of the respective end plates 14 by screws, bolts, etc., thereby functioning as a fastening member. Thereby, in the battery module 10, the upper part of the stacked battery cells 12 is integrally sandwiched and held by a pair of end plates 14.

[0027] The cooler 24 is spanned between a pair of end plates 14 below the battery cells 12, and both ends of the cooler 24 in the arrangement direction of the battery cells 12 are connected to the lower end portions of the respective end plates 14. Thereby, in the battery module 10, the lower part of the stacked battery cells 12 is integrally sandwiched and held by a pair of end plates 14.

[0028] In the battery module 10, a required restraint load is applied to each of the battery cells 12 by a pair of end plates 14 connected to each of the restraint band 22 and the cooler 24.

[0029] A heat conductive material 26 is disposed on the surface of the cooler 24 on the side of the battery cell 12, and each of the battery cells 12 is thermally connected to the cooler 24 via the heat conductive material 26. Thereby, the cooler 24 can exchange heat with each of the battery cells 12 via the heat conductive material 26. Note that the lower surface of the battery cell 12 may be directly in contact with the cooler 24 without passing through the heat conductive material 26 in the battery module 10.

[0030] By the way, in the battery module 10, as the metal plate 18, a metal (for example, iron, steel, stainless steel, aluminum, copper, etc.) having a thermal conductivity ka (1 / (W·m -1 ·K -1 )) higher than the thermal conductivity kb (1 / (W·m -1 ·K -1 )) of the heat insulating member 20 is used (ka>kb). For example, while the thermal conductivity kb of the heat insulating member 20 is 0.05 or less (kb≦0.05), the metal plate 18 has a thermal conductivity ka of 15 or more (ka≧15).

[0031] In the battery module 10, as the restraint band 22, a metal material having a thermal conductivity kc (1 / (W·m -1 ·K -1 )) higher than the thermal conductivity kb of the heat insulating member 20 is used (kc>kb). Further, in the battery module 10, also in the heat conductive material 26, a member such as a resin or a metal having a thermal conductivity kd (1 / (W·m -1 ·K -1 )) higher than the thermal conductivity k b of the heat insulating member 20 is used (kd>kb).

[0032] The metal plate 18 is composed of a vertical intermediate portion 18A as a first portion and at least one end portion 18B in the vertical direction as a second portion. In the embodiment, both sides in the vertical direction are the end portions 18B as the second portion, but the second portion may be at least the lower side (the cooler 24 side).

[0033] In the metal plate 18, the intermediate portion 18A is substantially flat-plate-shaped, and in the metal plate 18, substantially the entire surface of each of the intermediate portions 18A is in surface contact with the heat insulating member 20 and is in close contact therewith. Further, in the metal plate 18, the end portion 18B spreads in the stacking direction in a top view, and in the end portion 18B, the upper or lower surface is a flat surface 28 along the stacking direction.

[0034] In the metal plate 18, the flat surface 28 of the lower end portion 18B of the metal plate 18 is in surface contact with the upper surface of the cooler 24 and is connected thereto. Further, in the metal plate 18, the flat surface 28 of the upper end portion 18B is in surface contact with the lower surface of the restraint band 22 and is connected thereto. Thereby, the metal plate 18 is capable of heat exchange with the heat insulating member 20 and is also capable of heat exchange with each of the restraint band 22 and the cooler 24.

[0035] In the cooler 24, for example, a refrigerant pipe (not shown) through which a refrigerant circulates is laid inside, and in the cooler 24, the outer peripheral portion (at least the outer peripheral portion on the battery cell 12 side) is cooled by the circulation of the refrigerant supplied to the refrigerant pipe. Thereby, the cooler 24 cools each of the battery cells 12 and each of the metal plates 18 and dissipates the heat generated from the battery cells 12.

[0036] Note that the refrigerant circulated inside the cooler 24 may be a gas or a liquid, and the cooler 24 is not limited to a refrigerant type and may be an air type or the like as long as it has a required cooling function.

[0037] Next, the operation of the present embodiment will be described. In the battery module 10, a plurality of battery cells 12 are stacked and electrically connected in series or in parallel. Thereby, in the battery module 10, each of the battery cells 12 discharges to output power of a required DC voltage. Further, in the battery module 10, since secondary batteries are used for the battery cells 12, each of the battery cells 12 is charged when DC power is input.

[0038] On the one hand, each of the battery cells 12 generates heat during discharge and charging, causing the temperature to rise. In the battery cell 12, if the appropriate temperature range is greatly exceeded, the battery performance such as discharge performance and charging performance is likely to deteriorate. For example, in the battery module 10 in which a plurality of battery cells 12 are stacked, when the temperature of one battery cell 12 greatly exceeds the appropriate temperature, if the heat of this battery cell 12 is transmitted to the adjacent battery cell 12, it will cause a deterioration in the battery performance of the adjacent battery cell 12.

[0039] In the battery module 10, a metal plate 18 is disposed between the battery cells 12 adjacent in the stacking direction, and a heat insulating member 20 is disposed between the battery cell 12 and the metal plate 18. The metal plate 18 has a higher thermal conductivity than the heat insulating member 20. Further, the metal plate 18 is in surface contact with the heat insulating member 20, and the lower end portion is thermally connected to the cooler 24.

[0040] Therefore, in the battery module 10, the heat insulating member 20 suppresses the heat dissipation of the battery cell 12. Further, in the battery module 10, the heat of the battery cell 12 is transmitted from the heat insulating member 20 to the metal plate 18, and the metal plate 18 transmits the heat to the cooler 24. Thereby, in the battery module 10, the heat of the battery cell 12 is dissipated through the metal plate 18, and the radiant heat emitted from one battery cell 12 can be blocked from being transmitted to the battery cell 12 adjacent in the stacking direction. Therefore, in the battery module 10, even if the temperature of any one of the battery cells 12 rises, it is possible to prevent the temperature of the battery cell 12 adjacent in the stacking direction from rising.

[0041] Here, in the battery module 10, an intermediate portion 18A that is in surface contact with the heat insulating member 20 and an end portion 18B that faces the cooler 24 are provided on the metal plate 18. The metal plate 18 has a length dimension along the stacking direction in the vertical view of the end portion 18B that is longer than the length dimension (thickness dimension) of the intermediate portion 18A. A flat surface 28 is formed on the end portion 18B of the metal plate 18 on the cooler 24 side.

[0042] The flat surface 28 of the end portion 18B of the metal plate 18 is in surface contact with and connected to the cooler 24. As a result, the contact area of the metal plate 18 with the cooler 24 is increased as compared with the case where the end portion without the flat surface 28 comes into contact. Further, in the battery module 10, since the thermal conductivity of the metal plate 18 is higher than that of the heat insulating member 20, heat transfer from the metal plate 18 to the heat insulating member 20 is suppressed.

[0043] As a result, in the battery module 10, the heat exchange efficiency between the metal plate 18 and the cooler 24 is improved, and in the battery module 10, the heat dissipation property of the metal plate 18 is effectively improved.

[0044] Further, in the battery module 10, a metal restraint band 22 is disposed on the side opposite to the cooler 24 with the battery cell 12 interposed therebetween. Further, an end portion 18B is provided on the metal plate 18 on the side of the restraint band 22, and the flat surface 28 of the end portion 18B of the metal plate 18 is in surface contact with the restraint band 22.

[0045] Therefore, in the battery module 10, heat can be efficiently transferred from the metal plate 18 to the restraint band 22, and the heat of the metal plate 18 can be dissipated from the restraint band 22. As a result, in the battery module 10, the heat generated from the battery cell 12 can be transferred from the metal plate 18 to the restraint band 22 and dissipated from the restraint band 22, so that the heat dissipation property of the metal plate 18 can be more effectively improved.

[0046] Therefore, in the battery module 10, it is possible to effectively suppress the occurrence of a temperature rise in each battery cell 12. Further, in the battery module 10, it is possible to block the radiant heat emitted from one battery cell 12 from being transmitted to the adjacent battery cell 12, and effectively suppress the occurrence of various temperature problems such as a decrease in battery performance due to a temperature rise in one battery cell 12.

[0047] Further, in a vehicle, the cell case in which the battery cells 12 (battery stack 16) are housed may have a potential with respect to the vehicle body. For this reason, if the battery cell 12 is in contact with a material having conductivity, there is a possibility that a failure such as electric leakage may occur.

[0048] In the battery module 10, an insulating heat insulating material is used for the heat insulating member 20 disposed around the battery cell 12 and in contact with the battery cell 12, and the battery cell 12 is surrounded by the insulating heat insulating member 20. Thereby, in the battery module 10, occurrence of failures such as leakage of the battery cell 12 is suppressed. Note that a heat insulating material having conductivity can be used for the heat insulating member 20. In this case, methods such as applying an insulating paint to the restraining band 22 in contact with the heat insulating member 20 or the inner surface of the cell case in which the battery cell 12 is accommodated together with the heat insulating member 20, or performing a coating using an insulating film may be applied.

[0049] Note that, in the battery module 10 according to the present embodiment, end portions 18B are formed on each of the restraining band 22 side and the cooler 24 side of the metal plate 18. However, the second portion of the metal plate only needs to be provided at least on the cooler side. Thereby, in the battery module, the cooling performance of the metal plate can be improved, so that effective cooling of the battery cell using the cooler and blocking of radiant heat become possible.

Description of Reference Numerals

[0050] 10 Battery module 12 Battery cell 14 End plate 18 Metal plate 18A Intermediate portion (first portion) 18B End portion (second portion) 20 Heat insulating member 22 Restraining band (connecting member) 24 Cooler 28 Flat surface

Claims

1. A plurality of battery cells stacked in a first direction, Metal plates disposed on both sides of each of the battery cells in the first direction, Heat insulating members disposed between each of the battery cells and the metal plates and contacting each of the metal plates and the battery cells, A cooler disposed in a second direction intersecting the first direction with respect to each of the battery cells for cooling each of the battery cells, comprising The metal plate includes a first portion that is in surface contact with the heat insulating member and a second portion at the end of the first portion on the second direction side, The second portion is formed such that the length in the first direction is longer than that of the first portion when viewed from the second direction and is in surface contact with the cooler. A battery module.

2. End plates disposed in pairs on both sides in the first direction with the stacked battery cells interposed therebetween, A metal connecting member disposed on the side opposite to the cooler with respect to the battery cells in the second direction and connecting the end plates on both sides in the first direction, further comprising The battery module according to claim 1, wherein the second portion on the side of the connecting member of the metal plate is in surface contact with the connecting member.

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