Battery module

Abstract

The utility model provides a battery module of which the heat dissipation performance of a battery unit is improved. The battery module includes 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, and heat insulating members disposed between the battery cells and the metal plates and in contact with the metal plates and the battery cells. And 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, the metal plate including a first portion in surface contact with the heat insulating member and a second portion at a second direction side end portion of the first portion, the second portion being formed such that a length in the first direction is longer than that in the first direction when viewed from the second direction. And is in surface contact with the cooler.

Description

TECHNICAL FIELD

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

[0002] In a battery pack described in Japanese Patent Application Publication No. 2022-141506, a plurality of battery cells are stored inside a battery case, and a heat control sheet (a heat control sheet for a battery pack) is interposed between adjacent battery cells. The heat control sheet is provided with an intermediate layer between a pair of surface layers, and a thermal insulation material is interposed between the intermediate layer and each surface layer. The surface layers and the intermediate layer use a material having a lower emissivity and a higher thermal conductivity than the thermal insulation material. SUMMARY

[0003] However, in the heat control sheet, if the heat of the surface layer or the intermediate layer is not radiated but accumulated, there is a concern that the surface layer or the intermediate layer will heat the thermal insulation material or the battery cells, not only the battery cells that have already heated, but also the battery cells adjacent to the battery cells. Therefore, in a battery module using a plurality of battery cells, there is room for improvement in heat dissipation of the battery cells.

[0004] The present disclosure was completed in view of the above facts, and aims to provide a battery module in which the heat dissipation of the battery cells is improved.

[0005] A battery module according to a first aspect includes: battery cells stacked in a first direction; metal plates disposed on both sides of each of the battery cells in the first direction; thermal insulation members disposed between the battery cells and the metal plates, respectively, and in contact with the metal plates and the battery cells, respectively; and coolers disposed in a second direction crossing the first direction with respect to each of the battery cells, for cooling each of the battery cells, the metal plates including a first portion in contact with the thermal insulation members and a second portion of a side end portion of the first portion in the second direction, the second portion being formed to have a longer length in the first direction than the first portion when viewed in the second direction, and being in contact with the coolers.

[0006] In the first aspect, a plurality of battery cells are stacked in the first direction. In each of the battery cells, a metal plate is disposed on both sides in the first direction, and a thermal insulation member is disposed between each of the battery cells and the metal plate. Thus, the thermal insulation members, the metal plates, and the thermal insulation members are sequentially disposed between the battery cells adjacent in the first direction.

[0007] Further, the cooler is arranged in a second direction intersecting the first direction with respect to each battery cell, and each battery cell is capable of being cooled by the cooler. Therefore, the radiant heat emitted from the battery cell can be suppressed from being transmitted to the battery cell adjacent in the first direction by the thermal insulation member, and heat can be transmitted from the thermal insulation member to the cooler via the metal plate.

[0008] Here, the metal plate includes a first portion in surface contact with the thermal insulation member, and a second portion of an end portion of the first portion on a second direction side, the second portion being formed to have a length in the first direction longer than the first portion when viewed in the second direction, and being in surface contact with the cooler.

[0009] Thus, compared to a case where only the end surface of the metal plate is in contact with the cooler, the contact area between the metal plate and the cooler can be increased, and the heat dissipation of the metal plate can be improved, so the radiant heat emitted from the battery cell can be effectively blocked from being transmitted to the battery cell adjacent in the first direction by the metal plate.

[0010] The second aspect is the battery module of the first aspect further comprising: end plates arranged in pairs on both sides of the first direction sandwiching the stacked battery cells; and a metal connecting member arranged on the opposite side of the cooler in the second direction with respect to the battery cells, connecting the end plates on both sides of the first direction to each other, the second portion of the metal plate on the connecting member side being in surface contact with the connecting member.

[0011] In the battery module of the second aspect, the end plates are arranged in pairs on both sides of the first direction sandwiching the stacked battery cells, and the connecting member is arranged on the opposite side of the cooler in the second direction with respect to the battery cells. The connecting member is metal, and connects the end plates on both sides of the first direction to each other. Further, the second portion of the metal plate on the connecting member side is in surface contact with the connecting member.

[0012] Thus, heat emitted from the battery cell can be transmitted to the connecting member via the metal plate, and dissipated from the connecting member. At this time, since heat can be effectively transmitted from the metal plate to the connecting member, the heat dissipation of the metal plate can be further improved.

[0013] According to the present disclosure, by connecting the metal plate arranged between the battery cells adjacent in the first direction with the cooler, heat emitted from the battery cell can be dissipated from the metal plate. At this time, by connecting the second portion of the metal plate with the cooler, the heat transmission area between the metal plate and the cooler can be increased, so there is an effect that the radiant heat emitted from the battery cell can be effectively blocked from being transmitted to the battery cell adjacent in the first direction by the metal plate.

[0014] In addition, in the present disclosure, a connecting member made of metal is provided, and the second portion of the metal plate is in contact with the connecting member. Thus, since heat can be efficiently transferred from the metal plate to the connecting member, it is possible to further improve the heat dissipation performance of the metal plate. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a side view showing the main part of the battery module according to the present embodiment. DETAILED DESCRIPTION

[0016] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings.

[0017] Figure 1 is a side view showing the main part of the battery module 10 according to the present embodiment. In addition, in the drawings, the stacking direction as the first direction is indicated by an arrow X, and the up-down direction as the second direction intersecting the first direction is indicated by an arrow Z. In addition, in the present embodiment, the direction intersecting the stacking direction (arrow X direction) and the up-down direction (arrow Z direction) is taken as the width direction, and the width direction corresponds to the front-back direction of the paper surface.

[0018] The battery module 10 according to the present embodiment is formed by housing one or a plurality of battery packs (both not shown) as a battery group in a case (battery case). The battery pack using the battery module 10 is mounted, for example, on a vehicle equipped with an electric motor (electric motor), and outputs electric power for driving the electric motor. As such a vehicle, as long as it is equipped with an electric motor, it can be 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), or the like.

[0019] As shown in Figure 1 , the battery module 10 is provided with a plurality of battery cells 12 and a pair of end plates 14. The plurality of battery cells 12 are each formed in a substantially rectangular parallelepiped shape, and are arranged in the stacking direction to form a battery stack 16.

[0020] One of the pair of end plates 14 is disposed on one side in the arrangement direction of the battery cells 12, and the other is disposed on the other side in the arrangement direction of the battery cells 12. Thus, in the battery module 10, the battery stack 16 in which a plurality of battery cells 12 are stacked between the pair of end plates 14 is disposed. In the battery module 10, the battery stack 16 connects a plurality of battery cells 12 in series or in parallel, and can output electric power of a predetermined voltage.

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

[0022] The battery cells 12 can use a secondary battery such as a lithium-ion battery. In addition, the battery cells 12 are not limited to lithium-ion batteries, and various secondary batteries such as all-solid batteries, lead batteries, nickel-cadmium batteries, and nickel-hydrogen batteries can be applied, for example. Also, the battery cells 12 are not limited to secondary batteries, and primary batteries (for example, manganese dry batteries, graphite fluoride lithium primary batteries, manganese dioxide lithium primary batteries, and the like) can be applied.

[0023] In the battery module 10, metal plates 18 as heat transfer portions and heat dissipation portions are arranged between the battery cells 12 adjacent in the stacking direction and between the battery cells 12 and the end plates 14. In addition, in the battery module 10, thermal insulation 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. Thus, in the battery module 10, the battery cells 12 whose thermal insulation members 20, metal plates 18, and thermal insulation members 20 are overlaid in this order in the stacking direction and which are adjacent in the stacking direction, and the battery cells 12 and the end plates 14 are arranged.

[0024] The thermal insulation members 20 can use a thermal insulation material having electrical conductivity, but a thermal insulation material having electrical insulation is preferably used. In the battery module 10, a thermal insulation material having electrical insulation is used as the thermal insulation members 20.

[0025] On the other hand, the battery module 10 has a restraint belt 22 as a connecting member and a cooler 24 as a cooler. The restraint belt 22 is erected between the pair of end plates 14 on the upper side of the battery cells 12, and the end portions of the restraint belt 22 on both sides in the arrangement direction of the battery cells 12 are connected to the upper end portions of the end plates 14, respectively.

[0026] The restraint belt 22 is made of metal, and the restraint belt 22 is formed in a belt shape, for example, and functions as a fastening member by being fastened and fixed to the upper end portions of the end plates 14 by the end portions on both sides in the length direction using screws, bolts, or the like, respectively. Thus, in the battery module 10, the upper portions of the stacked battery cells 12 are integrally clamped and held by the pair of end plates 14.

[0027] The cooler 24 is erected between the pair of end plates 14 below the battery cells 12, and the end portions of the cooler 24 in the arrangement direction of the battery cells 12 are connected to the lower end portions of the end plates 14, respectively. Thus, in the battery module 10, the lower portions of the stacked battery cells 12 are integrally clamped and held by the pair of end plates 14.

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

[0029] In the cooler 24, a surface on the battery cell 12 side is provided with a heat transfer material 26, and the battery cell 12 is thermally connected with the cooler 24 via the heat transfer material 26, respectively. Thus, the cooler 24 is capable of heat exchanging with each battery cell 12 via the heat transfer material 26. Further, the battery module 10 can also directly contact the lower surface of the battery cell 12 with the cooler 24 without the heat transfer material 26.

[0030] As the metal plate 18, a metal (for example, iron, steel, stainless steel, aluminum, copper, or the like) having a thermal conductivity ka (1 / (W·m -1 ·K -1 ) higher than a thermal conductivity kb (1 / (W·m -1 ·K -1 ) of the thermal insulation member 20 (ka > kb) can be used. For example, the thermal conductivity kb of the thermal insulation member 20 is 0.05 or less (kb ≤ 0.05), and in relation thereto, the thermal conductivity ka of the metal plate 18 is 15 or more (ka ≥ 15).

[0031] In the battery module 10, as the constraint band 22, a metal material having a thermal conductivity kc (1 / (W·m -1 ·K -1 ) higher than the thermal conductivity kb of the thermal insulation member 20 (kc > kb) can be used. Also, in the battery module 10, in the heat transfer 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 kb of the thermal insulation member 20 (kd > kb) is used.

[0032] The metal plate 18 is composed of a middle portion 18A in the up-down direction as a first portion and an end portion 18B in at least one of the up-down direction as a second portion. Further, in the embodiment, both sides in the up-down direction are the end portions 18B as the second portion, but the second portion can be at least the lower side (the cooler 24 side).

[0033] In the metal plate 18, the middle portion 18A is substantially flat, and substantially the entire surface of each of the middle portions 18A of the metal plate 18 is in surface contact and close contact with the thermal insulation member 20. In addition, the end portion 18B is expanded in the stacking direction when viewed from above, and the surface of the upper side or the lower side on the end portion 18B becomes a flat surface 28 along the stacking direction.

[0034] The flat surface 28 of the lower end portion 18B of the metal plate 18 is connected in surface contact with the upper surface of the cooler 24. In addition, the flat surface 28 of the upper end portion 18B of the metal plate 18 is connected in surface contact with the lower surface of the restraint band 22. Thus, the metal plate 18 can exchange heat with the thermal insulating member 20, and can exchange heat with each of the restraint band 22 and the cooler 24.

[0035] The cooler 24 is, for example, internally provided with a refrigerant pipe (not shown) that circulates a refrigerant, and the cooler 24 cools the outer peripheral portion (at least the outer peripheral portion of the battery cell 12 side) by circulating the refrigerant supplied to the refrigerant pipe. Thus, the cooler 24 cools each of the battery cell 12 and the metal plate 18, and dissipates heat emitted from the battery cell 12.

[0036] Further, the refrigerant circulating in the cooler 24 can be a gas or a liquid, and the cooler 24 is not limited to a refrigerant type, but can be an air type or the like as long as it has a desired cooling function.

[0037] Next, the effects of the present embodiment will be described.

[0038] In the battery module 10, a plurality of battery cells 12 are stacked and electrically connected in series or in parallel. Thus, in the battery module 10, a desired direct-current voltage power is output by discharging each of the battery cells 12. In addition, in the battery module 10, a direct-current power is input by using a secondary battery in the battery cell 12, and thus each of the battery cells 12 is charged.

[0039] On the other hand, each of the battery cells 12 generates heat and increases in temperature at the time of discharging and at the time of charging. In the battery cell 12, if the temperature greatly exceeds an appropriate temperature range, the battery performance such as discharging performance and charging performance is easily reduced. 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 an appropriate temperature, if the heat of the battery cell 12 is transferred to an adjacent battery cell 12, the adjacent battery cell 12 is caused to have a reduction in battery performance.

[0040] In the battery module 10, the metal plate 18 is disposed between the battery cells 12 adjacent in the stacking direction, and the thermal insulating member 20 is disposed between the battery cell 12 and the metal plate 18, and the metal plate 18 has a higher thermal conductivity than the thermal insulating member 20. In addition, the metal plate 18 is in surface contact with the thermal insulating member 20, and the lower end portion is thermally connected to the cooler 24.

[0041] Therefore, in the battery module 10, the heat of the battery cells 12 is suppressed from being radiated to the battery cells 12 adjacent in the stacking direction. Therefore, in the battery module 10, even if temperature rise occurs in any one of the battery cells 12, temperature rise can be prevented from occurring in the battery cells 12 adjacent in the stacking direction.

[0042] In the battery module 10, the metal plate 18 is provided with an intermediate portion 18A that is in surface contact with the thermal insulating member 20 and an end portion 18B that is opposed to the cooler 24. The length dimension of the end portion 18B of the metal plate 18 in the stacking direction viewed in the up-down direction is larger than the length dimension (thickness dimension) of the intermediate portion 18A, and a flat surface 28 is formed on the end portion 18B of the metal plate 18 on the cooler 24 side.

[0043] The flat surface 28 of the end portion 18B of the metal plate 18 is connected in surface contact with the cooler 24. Therefore, compared to the case where the end portion is not provided with the flat surface 28, the contact area of the metal plate 18 with the cooler 24 is enlarged. In addition, in the battery module 10, since the thermal conductivity of the metal plate 18 is higher than the thermal conductivity of the thermal insulating member 20, heat transfer from the metal plate 18 to the thermal insulating member 20 is suppressed.

[0044] Therefore, in the battery module 10, the heat exchange efficiency between the metal plate 18 and the cooler 24 is improved, and the heat dissipation property of the metal plate 18 is effectively improved in the battery module 10.

[0045] In addition, in the battery module 10, the metal-made restraint band 22 is arranged on the side opposite to the cooler 24 with the battery cell 12 interposed therebetween. In addition, on the metal plate 18, the end portion 18B is provided on the restraint band 22 side, and the flat surface 28 of the end portion 18B of the metal plate 18 is in surface contact with the restraint band 22.

[0046] 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. Therefore, since in the battery module 10, heat emitted 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, the heat dissipation property of the metal plate 18 can be more effectively improved.

[0047] Therefore, in the battery module 10, the temperature rise of each battery cell 12 can be effectively suppressed. Also, in the battery module 10, the transfer of the radiant heat emitted from one battery cell 12 to the adjacent battery cell 12 can be blocked, and various temperature problems such as the reduction of the battery performance due to the temperature rise of one battery cell 12 can be effectively suppressed.

[0048] Also, in the vehicle, the cell case in which the battery cell 12 (battery stack 16) is housed can have an electric potential with respect to the vehicle body. Therefore, if the battery cell 12 contacts with the material having the electric conductivity, the trouble such as the electric leakage can occur.

[0049] In the battery module 10, the battery cell 12 is surrounded by the heat insulating member 20 having the insulation, using the heat insulating material having the insulation for the heat insulating member 20 arranged around the battery cell 12 and contacting with the battery cell 12. Thereby, in the battery module 10, the trouble such as the electric leakage of the battery cell 12 can be suppressed. Further, the heat insulating member 20 can use the heat insulating material having the electric conductivity. In this case, the method such as the application of the restraint belt 22 contacting with the heat insulating member 20, the inner surface of the cell case in which the battery cell 12 is housed together with the heat insulating member 20 is coated with the paint having the insulation, or the coating together with the thin film having the insulation can be applied.

[0050] Further, in the battery module 10 according to the present embodiment, the end portion 18B is formed on the restraint belt 22 side and the cooler 24 side of the metal plate 18, respectively. However, the second portion of the metal plate can be provided at least on the cooler side. Thereby, in the battery module, the cooling performance of the metal plate can be improved, so the effective cooling of the battery cell using the cooler and the blocking of the radiant heat can be achieved.

Claims

1. A battery module, characterized by, Possessing: a battery cell having a plurality of cells stacked in a first direction; a metal plate disposed on both sides of each of the battery cells in the first direction; a thermal insulating member disposed between each of the battery cells and the metal plate and in contact with each of the metal plate and the battery cell; 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, the metal plate includes a first portion in surface contact with the thermal insulating member and a second portion of a side end portion of the first portion in the second direction, the second portion is formed to have a length in the first direction longer than the first portion when viewed in the second direction and is in surface contact with the cooler.

2. The battery module of claim 1, wherein, Further possessing: an end plate disposed in pairs on both sides of the stacked battery cells in the first direction sandwiching the stacked battery cells; a metal connecting member disposed on the opposite side of the cooler from the battery cell in the second direction connecting the end plates on both sides of the first direction to each other, the second portion of the metal plate on the side of the connecting member is in surface contact with the connecting member.

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