JP6234171B2 - Battery module - Google Patents

Description

The present invention relates to a battery module having a heat conduction device that conducts heat of a battery to a heat sink , for example.

  An electric vehicle or a hybrid vehicle (hereinafter referred to as an electric vehicle) includes a battery. In an electric vehicle, it is important to secure an appropriate amount of battery discharge in order to improve the cruising distance. The battery discharges most efficiently when the ambient temperature in which the battery is installed is, for example, 30 to 50 ° C.

  When a plurality of batteries are connected in series and there is a variation in the ambient temperature of each battery, the efficiency is remarkably lowered, so that the ambient temperature in which each battery is installed needs to be made uniform.

  For example, as a technique for equalizing the ambient temperature in which each battery is installed, a technique is known in which air is separately supplied to each battery (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 06-261422

  For example, when air is supplied to each battery to cool it, it is necessary to prepare a flow path for air to pass around each battery, and there is a problem that a large space is required. Since it cools, there exists a problem that cooling efficiency is bad.

  This invention is made | formed in view of the said subject, and it aims at providing the technique which can improve cooling efficiency.

  To achieve the above object, a heat conduction device according to an embodiment of the present invention is a heat conduction device that conducts heat from a heating element to a heat radiating member, and includes a rubber-like elastic body. A heat conductive rubber layer that can be deformed according to the surface, and a metal layer that is made of metal, is laminated on the opposite side of the heat conductive rubber layer from the heat generating element, and is thermally connected to the heat radiating member.

  The heat conducting device according to another embodiment further has a heat insulating layer that has a lower thermal conductivity than the heat conducting rubber layer and is laminated on the opposite side of the metal layer from the heating element.

  In the heat conduction device according to another embodiment, the rubber-like elastic body is an elastic body containing silicone rubber.

  In the heat conducting device according to another embodiment, the heat insulating layer is a silicone rubber layer having voids in the layer.

  The heat conducting device according to another embodiment is also configured such that the metal layer has flexibility. In the heat conducting device according to another embodiment, the metal layer also has voids in the layer. In the heat conduction device according to another embodiment, the metal layer is a punched metal plate.

  In the heat conduction device according to another embodiment, the heating element is a battery cell.

  A heat conduction device according to another embodiment is a device provided in a battery module having a plurality of battery cells, and other battery cells are arranged on the side of the heat insulating layer opposite to the heating element.

  In addition, a battery module according to an embodiment of the present invention includes any one of the above-described heat conduction devices and one or more battery cells.

  According to the present invention, the heat conductive rubber layer is in close contact with the heating element, and the heat of the heating element can be efficiently conducted to the metal layer, so that the cooling efficiency of the heating element can be improved.

FIG. 1 is a diagram for explaining the principle of a heat conduction device according to an aspect of the present invention. FIG. 2 is a cross-sectional view of a battery module for an electric vehicle including the heat conduction device according to the first embodiment. FIG. 3 is a cross-sectional view of a battery module for an electric vehicle including the heat conduction device according to the second embodiment. FIG. 4 is a cross-sectional view of a battery module for an electric vehicle including a heat conduction device according to the third embodiment. FIG. 5 is a cross-sectional view of a battery module for an electric vehicle including a heat conduction device according to the fourth embodiment.

  Embodiments of the present invention will be described with reference to the drawings. The embodiments described below do not limit the invention according to the claims, and all the elements and combinations described in the embodiments are indispensable for the solving means of the invention. Not always.

<Principle of one aspect of the present invention>
First, the principle of the heat conduction device according to one aspect of the present invention will be described.

  FIG. 1 is a diagram for explaining the principle of a heat conduction device according to an aspect of the present invention.

  The heat conduction device according to one aspect of the present invention is used, for example, in a battery pack for an electric vehicle. The battery pack has a battery module including the battery cell 10. The battery cell 10 is an example of a heating element, and is, for example, a sheet-like battery whose exterior is made of a laminate film. The surface of the battery cell 10 has unevenness and curvature.

  The heat conduction device 1 includes a heat conduction rubber layer 2 disposed so as to be in surface contact with one surface (upper surface in FIG. 1) of the battery cell 10 to be radiated, and the heat conduction rubber layer 2 on the battery cell 10 side. The metal layer 3 is laminated on the surface in the opposite direction (hereinafter referred to as the upward direction), and the heat insulating layer 4 is laminated on the metal layer 3 in the upward direction. The heat conductive rubber layer 2 and the metal layer 3 are bonded by, for example, an adhesive. Moreover, the metal layer 3 and the heat insulation layer 4 are adhere | attached with an adhesive agent, for example.

  The heat conductive rubber layer 2 has a substantially rectangular planar shape, and has a thickness of 0.5 to 2 mm, for example. The heat conductive rubber layer 2 includes a rubber-like elastic body formed so as to have heat conductivity. For example, the heat conductive rubber layer 2 is configured by blending a rubber-like elastic body with a filler having high heat conductivity. The thermal conductivity of the heat conductive rubber layer 2 is at least higher than that of air. The heat conductive rubber layer 2 is relatively flexible (durometer type A hardness according to the measurement method of JISK6253 is preferably 10 to 40), and can be deformed according to the surface of the battery cell 10. Therefore, the heat conductive rubber layer 2 has high adhesion to the surface of the battery cell 10 and can receive heat from the battery cell 10 efficiently.

  This rubber-like elastic body is a thermosetting elastomer such as urethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene rubber or styrene butadiene rubber; urethane type, ester type, styrene type, olefin type, butadiene type or It is preferably composed of a fluorine-based thermoplastic elastomer; or a composite thereof or the like, and particularly preferably composed of silicone rubber having excellent heat resistance.

  As the heat conductive rubber layer 2, for example, TC-100THS, a low hardness heat dissipation silicone pad manufactured by Shin-Etsu Chemical Co., Ltd., can be used. TC-100THS has an Asker C hardness of 30 (corresponding to a durometer type A hardness of 10 to 15 according to the measurement method of JISK6253) and a thermal conductivity (measurement method: ISO 22007-2) of 2.1 W / m · K. It is.

  In addition, the dimension and hardness of the heat conductive rubber layer 2 are only examples, and are not limited thereto. For example, in order to increase the heat transfer amount from the battery cell 10 to the metal layer 3, the heat conductive rubber layer 2 has a thickness that can secure a certain degree of adhesion with the upper surface of the battery cell 10 to be radiated. It ’s better to make it thinner. Further, the hardness of the heat conductive rubber layer 2 may be lower than the above hardness as long as it does not flow out or detach when pressed, and it can secure a certain degree of adhesion to the upper surface of the battery cell 10 to be radiated. For example, it may be higher than the above hardness.

  The metal layer 3 is composed of, for example, a metal plate having a thickness of 0.2 mm (for example, a copper, aluminum, or tin plate). The heat conductivity of the metal layer 3 is higher than at least the heat conductivity of the heat conductive rubber layer 2. The metal which comprises the metal layer 3 is not restricted to these, A metal with high heat conductivity is preferable. Since the metal layer 3 affects the followability of the heat conductive rubber layer 2 to the surface of the battery cell 10, it is preferable that the metal layer 3 has relatively flexibility.

  The configuration and thickness of the metal layer 3 are not limited to these. The metal layer 3 may be a metal member having a void in the layer. More specifically, the metal layer 3 may be, for example, a punched metal plate, a mesh knitted with a metal wire, or a foam metal obtained by foaming a metal member. Alternatively, a porous metal made from a metal may be used. Such a metal layer 3 can have flexibility while maintaining a relatively high thermal conductivity.

  The metal layer 3 is thermally connected to a heat sink 5 which is an example of a heat radiating member. The heat sink 5 is made of, for example, aluminum. In the present embodiment, the heat sink 5 is connected on the metal layer 3, but is not limited to this, and may be connected via another member having high thermal conductivity, for example.

  The heat insulating layer 4 is composed of a member having a relatively low thermal conductivity, that is, a member having a thermal conductivity lower than that of at least the thermal conductive rubber layer 2. The heat insulation layer 4 is comprised by the silicone rubber which has a space | gap, for example. Thereby, it can reduce that the heat transmitted to the metal layer 3 is conducted above the heat insulation layer 4 through the heat insulation layer 4. The heat insulating layer 4 may be a foamed silicone rubber layer obtained by foaming silicone rubber. The thickness of the heat insulation layer 4 is, for example, 0.5 to 10 mm.

  When the heat insulating layer 4 is a foamed silicone rubber layer, for example, DM-TYPE of a silicone sponge sheet manufactured by Shin-Etsu Polymer Co., Ltd. can be used. DM-TYPE has a thermal conductivity of 0.11 W / m · K when the expansion ratio is 2 times, and 0.08 W / m · K when the expansion ratio is 4 times. In addition, the heat insulation layer 4 is not restricted to these materials, What is necessary is just a material with high heat insulation.

  Next, how the battery cell 10 is cooled through the heat conducting device 1 will be described.

  When the battery cell 10 is charged or discharged, the battery cell 10 generates heat. The heat generated from the battery cell 10 is transferred to the metal layer 3 through the heat conductive rubber layer 2 that is in close contact with the upper surface of the battery cell 10. Here, since the heat conductivity of the heat conductive rubber layer 2 is very high compared to the heat conductivity of air, heat can be transferred efficiently.

  Most of the heat transferred to the metal layer 3 is transferred to the heat sink 5 that is thermally connected, and is efficiently dissipated from the heat sink 5. Since the heat conductivity of the heat insulating layer 4 is low, the heat transferred from the metal layer 3 to the heat insulating layer 4 and transferred to the components on the heat insulating layer 4 is small. Therefore, it is possible to appropriately prevent the battery cell 10 from thermally affecting the components on the heat insulating layer 4.

<First Embodiment>
Next, the battery module that houses the heat conducting device according to the first embodiment will be described. Note that components common to the components described in the above-described principle of one aspect of the present invention are denoted by the same reference numerals, and description thereof is omitted as appropriate.

  FIG. 2 is a cross-sectional view of a battery module for an electric vehicle including the heat conduction device according to the first embodiment.

  The battery module 20A is a battery module that stores the battery cells 10 in a single layer (one row).

  The battery module 20A accommodates the battery cell 10 in a housing (a housing bottom 8a, housing side portions 8b and 8c, a housing upper portion 8d, etc.). The battery cell 10 is arrange | positioned through the heat insulation layer 6 on the housing | casing bottom part 8a. The heat insulating layer 6 is composed of a member having a relatively low thermal conductivity, that is, a member having a thermal conductivity lower than that of at least the heat conductive rubber layer 2. The heat insulating layer 6 may be a member similar to the heat insulating layer 4.

  A heat conductive rubber layer 2 is laminated on the upper surface of the battery cell 10 so as to be in surface contact, and a metal layer 3 is laminated on the heat conductive rubber layer 2. Part of the heat conductive rubber layer 2 and the metal layer 3 protrudes outside the housing.

  Further, a heat sink 5 is connected to a portion of the metal layer 3 protruding outside the housing via a heat conductive rubber layer 7. The metal layer 3 and the heat conductive rubber layer 7 are bonded by, for example, an adhesive. The heat conductive rubber layer 7 is a member similar to the heat conductive rubber layer 2, for example. According to the heat conductive rubber layer 7, the stability is improved as compared with the case where the heat sink 5 is directly connected to the metal layer 3. The metal layer 3 and the heat sink 5 may be directly connected without providing the heat conductive rubber layer 7. Further, the heat insulating layer 4 is laminated on the portion of the metal layer 3 in the housing.

  In the battery module 20 </ b> A, heat generated from the battery cell 10 is transmitted to the metal layer 3 through the heat conductive rubber layer 2 that is in close contact with the upper surface of the battery cell 10. Here, since the heat conductivity of the heat conductive rubber layer 2 is very high compared to the heat conductivity of air, heat can be transferred efficiently.

  Most of the heat transferred to the metal layer 3 is transferred to the heat sink 5 that is thermally connected via the heat conductive rubber layer 7 and efficiently radiated from the heat sink 5 to the outside. Further, since the heat conductivity of the heat insulating layer 4 is low, the heat transferred from the metal layer 3 to the housing through the heat insulating layer 4 is small. Moreover, since the heat conductivity of the heat insulation layer 6 is low, the heat transferred from the battery cell 10 to the housing via the heat insulation layer 6 is also small. For this reason, the housing itself is heated, and it is possible to appropriately prevent heat from being trapped in the housing.

<Second Embodiment>
Next, a battery module that houses a heat conduction device according to the second embodiment will be described. In addition, about the component which is common in 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted suitably.

  FIG. 3 is a cross-sectional view of a battery module for an electric vehicle including the heat conduction device according to the second embodiment.

  The battery module 20B is a battery module that stores the battery cells 10 in a single layer (one row).

  The battery module 20B accommodates the battery cell 10 in a housing (a housing bottom 8a, housing side portions 8b and 8c, a housing upper portion 8d, etc.). The battery cell 10 is disposed on the housing bottom 8 a via the heat insulating layer 4, the metal layer 3, and the heat conducting rubber layer 2. A part of the metal layer 3 and the heat conductive rubber layer 2 protrudes outside the housing. A heat sink 5 is connected to the lower surface of the portion of the metal layer 3 protruding from the housing via a heat conductive rubber layer 7. According to the heat conductive rubber layer 7, the stability is improved as compared with the case where the heat sink 5 is directly connected to the metal layer 3. The metal layer 3 and the heat sink 5 may be directly connected without providing the heat conductive rubber layer 7.

  A heat conductive rubber layer 2 is laminated on the upper surface of the battery cell 10 so as to be in surface contact, and a metal layer 3 is laminated on the heat conductive rubber layer 2. Part of the heat conductive rubber layer 2 and the metal layer 3 protrudes outside the housing.

  Further, a heat sink 5 is connected to a portion of the metal layer 3 that protrudes from the housing via a heat conductive rubber layer 7. According to the heat conductive rubber layer 7, the stability is improved as compared with the case where the heat sink 5 is directly connected to the metal layer 3. The metal layer 3 and the heat sink 5 may be directly connected without providing the heat conductive rubber layer 7. Further, the heat insulating layer 4 is laminated on the portion of the metal layer 3 in the housing.

  In the battery module 20B, heat generated from the battery cell 10 is transferred to the upper heat sink through the heat conductive rubber layer 2, the metal layer 3, and the heat conductive rubber layer 7 that are in close contact with the upper surface of the battery cell 10. 5 is transferred to the lower heat sink 5 through the heat conductive rubber layer 2, the metal layer 3 and the heat conductive rubber layer 7 which are in close contact with the lower surface. Heat is radiated from the heat sink 5 to the outside. Therefore, according to this battery module 20B, since heat is radiated from the plurality of heat sinks 5, the heat radiation effect is higher than that of the battery module 20A according to the first embodiment.

<Third Embodiment>
Next, a battery module that houses a heat conducting device according to the third embodiment will be described. In addition, about the component which is common in 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted suitably.

  FIG. 4 is a cross-sectional view of a battery module for an electric vehicle including a heat conduction device according to the third embodiment.

  The battery module 20C is a battery module that stores the battery cells 10 in a plurality of layers (two or more rows).

  The lowermost battery cell 10 (10B) is disposed on the housing bottom 8a via the heat insulating layer 6.

  A heat conductive rubber layer 2 is laminated on the upper surface of the battery cell 10B so as to be in surface contact, and a metal layer 3 is laminated on the heat conductive rubber layer 2. Part of the heat conductive rubber layer 2 and the metal layer 3 protrudes outside the housing. A heat insulating layer 4 is laminated on a portion of the metal layer 3 in the housing. Further, a heat sink 5 is connected to a portion of the metal layer 3 protruding outside the housing via a heat conductive rubber layer 7.

  Furthermore, on the heat insulation layer 4, the battery cell 10 (10A) of the upper layer is arrange | positioned. A heat conductive rubber layer 2 is laminated on the upper surface of the battery cell 10 </ b> A so as to be in surface contact, and a metal layer 3 is laminated on the heat conductive rubber layer 2. Part of the heat conductive rubber layer 2 and the metal layer 3 protrudes outside the housing. A heat insulating layer 4 is laminated on a portion of the metal layer 3 in the housing. Further, a heat sink 5 is connected to a portion of the metal layer 3 protruding outside the housing via a heat conductive rubber layer 7.

  In this battery module 20C, the heat generated from the battery cell 10A is transferred to the upper heat sink via the heat conductive rubber layer 2, the metal layer 3, and the heat conductive rubber layer 7 that are in close contact with the upper surface of the battery cell 10A. 5 is radiated from the heat sink 5 to the outside. Since the heat insulating layer 4 exists on the lower surface of the battery cell 10 </ b> A, there is little heat transfer through the heat insulating layer 4. The heat generated from the battery cell 10B is transmitted to the lower heat sink 5 through the heat conductive rubber layer 2, the metal layer 3, and the heat conductive rubber layer 7 that are in close contact with the upper surface of the battery cell 10B. The heat is radiated from the heat sink 5 to the outside. Since the heat insulating layer 6 exists on the lower surface of the battery cell 10 </ b> B, there is little heat transfer to the housing through the heat insulating layer 6.

  According to this battery module 20C, the heat of the accommodated multiple layers of battery cells 10 can be effectively dissipated.

<Fourth embodiment>
Next, a battery module that houses a heat conducting device according to the fourth embodiment will be described. In addition, about the component which is common in 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted suitably.

  FIG. 5 is a cross-sectional view of a battery module for an electric vehicle including a heat conduction device according to the fourth embodiment.

  The battery module 20D is a battery module that stores the battery cells 10 in a plurality of layers (two or more rows).

  The lowermost battery cell 10 (10B) is disposed on the housing bottom 8a via the heat insulating layer 6.

  A heat conductive rubber layer 2 is laminated on the upper surface of the battery cell 10B so as to be in surface contact, and a metal layer 3 is laminated on the heat conductive rubber layer 2. A part of the metal layer 3 protrudes outside the housing. The upper battery cell 10 (10A) is disposed on the portion of the metal layer 3 in the housing via the heat conducting rubber layer 2. A heat sink 5 is connected to a portion of the metal layer 3 that protrudes outside the housing. A heat insulating layer 6 is laminated on the upper surface of the battery cell 10A. A heat conductive rubber layer 7 may be interposed between the metal layer 3 and the heat sink 5.

  In the battery module 20D, heat generated from the battery cell 10A is transmitted to the heat sink 5 via the heat conductive rubber layer 2 and the metal layer 3 that are in close contact with the lower surface of the battery cell 10A, and is transmitted from the heat sink 5 to the outside. Heat is dissipated. On the other hand, the heat generated from the battery cell 10 </ b> B is transmitted to the heat sink 5 through the heat conductive rubber layer 2 and the metal layer 3 that are in close contact with the upper surface, and is radiated from the heat sink 5 to the outside. In addition, since the heat insulation layer 6 exists on the upper side of the battery cell 10A, the heat transfer to the housing through the heat insulation layer 6 is small. Moreover, since the heat insulation layer 6 exists under the battery cell 10B, the heat transfer to the housing is small through the heat insulation layer 6.

  According to the battery module 20D, the heat generated by the plurality of battery cells 10 is concentrated on the single heat sink 5 so as to dissipate the heat, so that the thickness, weight, and necessary space of the battery module 20D are effective. Can be reduced.

<Other embodiments>

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and can be applied to various other modes.

  For example, in the first to fourth embodiments, the battery cell has been described as an example of the heating element. However, the heating element is not limited to the battery cell, and the present invention is applied as long as it generates heat. Can do.

  In the first to fourth embodiments, the heat conductive rubber layer 2 and the metal layer 3 are bonded with an adhesive. However, the heat conductive rubber layer 2 and the metal layer 3 are laminated. The method is not limited to this. For example, the metal layer 3 is set in a predetermined mold, the rubber material of the uncured heat conductive rubber layer 2 is poured into the mold, and the heat conductive rubber layer 2 is poured into the metal layer 3. An insert molding method for forming the film may be used.

  The present invention can be used for cooling a battery.

DESCRIPTION OF SYMBOLS 1 Thermal conductive device 2 Thermal conductive rubber layer 3 Metal layer 4, 6, 7 Thermal insulation layer 5 Heat sink 10, 10A, 10B Battery cell 20A, 20B, 20C, 20D Battery module

Claims (4)

A battery module having one or more battery cells and a heat conduction device that conducts heat from the battery cells to the heat dissipation member,
The heat conducting device is
A heat conductive rubber layer comprising a rubber-like elastic body and deformable according to the surface of the battery cell ;
A metal layer made of metal, laminated on the opposite side of the heat conductive rubber layer to the battery cell, and thermally connected to the heat dissipation member ,
A heat insulating layer having a lower thermal conductivity than the thermally conductive rubber layer and laminated on the metal layer opposite to the battery cell;
Have
The battery cell is housed in a housing;
The heat conductive rubber layer and the metal layer have a part protruding outward from the housing,
The heat radiating member is connected to a portion of the metal layer protruding outside the housing via a heat conductive rubber layer different from the heat conductive rubber layer,
The battery module is formed by stacking the heat insulating layer on a portion of the metal layer in the housing.   The battery module according to claim 1, wherein the rubber-like elastic body is an elastic body containing silicone rubber.   The battery module according to claim 1, wherein the heat insulating layer is a silicone rubber layer having voids in the layer. The heat conducting device is provided in a battery module having a plurality of battery cells,
The battery module according to any one of claims 1 to 3 , wherein another battery cell is disposed on the opposite side of the battery cell with the heat insulating layer interposed therebetween .

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