JP2015022994A - Battery module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance temperature control performance of a battery module, by enhancing the heat exchange efficiency between a temperature control member, while suppressing up-sizing of the battery module.SOLUTION: A battery module includes a heat conduction member 50 disposed in a gap between the peripheral wall, becoming the connection surface with a water jacket, and an electric cell 40, and connecting the peripheral wall and the electric cell 40 thermally. The heat conduction member 50 is provided at the end of each electric cell 40, and has a thickness set to correspond with that of the electric cell 40.

Description

  The present invention relates to a battery module.

  2. Description of the Related Art Conventionally, an assembled battery configured by combining a plurality of battery modules is known as a battery mounted on an electric vehicle such as a hybrid vehicle or an electric vehicle. Each battery module has a configuration in which packaged single cells are housed in a case in a single state or in a stacked state, and for example, a lithium ion secondary battery is used as the single cell. In this type of battery module, it is common to perform temperature control of the battery module from the viewpoint of sufficiently exhibiting charge / discharge characteristics and suppressing performance deterioration.

  For example, Patent Document 1 discloses a temperature control device that performs temperature control on individual battery modules constituting an assembled battery. This assembled battery is configured by arranging a plurality of vertically placed battery modules in the horizontal direction. Each battery module is provided with heat transfer fins on the side surface facing the adjacent battery module, and each heat transfer fin is brazed to the heat transfer substrate provided on the bottom side of the assembled battery. Has been.

JP 2001-23703 A

  However, since the heat transfer fin as a temperature control member is provided in the side surface side of the battery module in Patent Document 1, the thickness in the stacking direction increases, leading to an increase in size. In particular, in an assembled battery in which battery modules are stacked, the increase in size becomes significant according to the number of stacked layers. On the other hand, if the heat transfer fin is thinned from the viewpoint of miniaturization, there is a problem that the heat exchange efficiency is lowered.

  This invention is made | formed in view of this situation, The objective is suppressing the enlargement of a battery module, and improving the heat exchange efficiency between temperature control members by improving the temperature control performance of a battery module. It is to improve.

  In order to solve this problem, the present invention provides a battery module capable of thermally connecting a temperature control member that performs heating or cooling. The battery module includes a heat conducting member that is disposed in a gap between the peripheral wall portion serving as a thermal connection surface with the temperature control member and the unit cell and thermally connects the peripheral wall unit and the unit cell. . This heat conducting member is provided at the end of the unit cell for each unit cell, and is set to a thickness corresponding to the unit cell.

  According to the present invention, it is possible to improve the temperature control performance of the battery module without increasing the size of the battery module and improving the heat exchange efficiency with the temperature control member.

Explanatory drawing which shows typically the structure of the assembled battery to which the battery module was applied Explanatory drawing of temperature control circuit connected to water jacket Explanatory drawing schematically showing the internal structure of the battery module The perspective view which shows the structure of a cell typically Explanatory drawing which shows a cell and a heat conductive member typically Explanatory drawing which shows typically the formation aspect of the heat conductive member with respect to a cell Explanatory drawing which shows typically the formation aspect of the heat conductive member with respect to a cell Explanatory drawing schematically showing the internal structure of the battery module Explanatory drawing which shows typically the formation aspect of the heat conductive member with respect to a cell

  FIG. 1 is an explanatory view schematically showing a configuration of an assembled battery 1 to which a battery module 10 according to the present embodiment is applied. The assembled battery 1 is used as a power source for an electric vehicle (not shown) that travels using the power of an electric motor, for example. The assembled battery 1 is disposed under the floor of a passenger compartment of an electric vehicle in a state of being housed in a battery case (not shown).

  The assembled battery 1 is configured by electrically connecting a plurality of battery modules 10. Each battery module 10 has a flat rectangular parallelepiped shape, and is stacked in the thickness direction in a vertically placed state. Specifically, the individual battery modules 10 are stacked along the left-right direction (Y direction) of the vehicle with the long sides directed in the front-rear direction (X direction) of the vehicle.

  End plates 2 are arranged on both sides in the stacking direction of the plurality of battery modules 10. A support plate 3 extending in the stacking direction (Y direction) of the battery modules 10 is disposed on the front side and the rear side of each battery module 10. The end plates 2 and the support plate 3 fix the battery modules 10 to each other and fix the battery modules 10 group to the battery case.

  The assembled battery 1 also includes a temperature control device 5 for heating or cooling the assembled battery 1, specifically, each battery module 10. For example, the temperature adjustment device 5 performs heat exchange between the cooled temperature adjustment medium and the assembled battery 1 when the surrounding environment is hot or when the battery module 10 generates heat due to charge / discharge. The battery 1 is cooled. Further, the temperature control device 5 heats the assembled battery 1 by exchanging heat between the heated temperature control medium and the assembled battery 1 when the surrounding environment such as a cold district is low temperature.

  The temperature adjustment device 5 includes a water jacket 6 through which a temperature adjustment medium (for example, water) for heat exchange flows, and a temperature adjustment circuit 200 (see FIG. 2) connected to the water jacket 6.

  The water jacket 6 is a temperature adjustment member that heats or cools the battery module 10 by thermally connecting to the assembled battery 1, specifically, the individual battery modules 10. The thermal connection between the water jacket 6 and each battery module 10 is performed by placing the water jacket 6 inside the bottom surface of the battery case and placing the assembled battery 1 on the water jacket 6. The battery 1 may be in direct contact with the bottom surface side of the battery 1 or may be performed via the battery case by disposing the water jacket 6 outside the bottom surface of the battery case.

  The water jacket 6 is formed in a plate shape from a material such as aluminum having excellent thermal conductivity, and has a rectangular shape corresponding to the outer shape on the bottom surface side of the assembled battery 1. Inside the water jacket 6 is formed an internal flow path through which the temperature adjustment refrigerant flows, an inlet portion 7a through which the temperature adjustment refrigerant flows into the internal flow path, and a temperature adjustment refrigerant flowing through the internal flow path. The temperature control flow path 200 is connected to the outlet portion 7b from which the gas flows out.

FIG. 2 is an explanatory diagram of the temperature control circuit 200 connected to the water jacket 6. The temperature adjustment circuit 200 is a closed circuit that circulates the temperature adjustment refrigerant flowing out from the outlet portion 7 b of the water jacket 6 to the inlet portion 7 a of the water jacket 6. The inlet 7a and outlet 7b of the water jacket 6 and the temperature control circuit 200 are connected by a rubber hose or the like. Thereby, even if the distance between the water jacket 6 and the temperature control circuit 200 changes due to vehicle vibration, no force is applied to each part.

  The temperature adjustment circuit 200 includes a low-temperature medium generator 210, an electric heater 220, a medium temperature sensor 230, a pump 240, a temperature adjustment medium passage 250 connecting them, a control device 260, and a battery temperature sensor 270. Composed. The temperature control circuit 200 operates in combination with, for example, the vehicle air conditioning system 300.

  The low-temperature medium generator 210 exchanges heat between the refrigerant of the vehicle air conditioning system 300 flowing into the low-temperature medium generator 210 and the temperature adjustment medium flowing into the low-temperature medium generator 210, so that the low-temperature temperature adjustment medium It is a heat exchanger to be generated. The electric heater 220 is a heater that receives a supply of electric power from a power source (not shown) and heats the temperature adjustment medium flowing in the temperature adjustment medium passage to generate a high-temperature temperature adjustment medium. The medium temperature sensor 230 is a sensor that detects the temperature of the temperature adjustment medium supplied to the assembled battery 1. The pump 240 is driven by receiving power from a power source (not shown), pumps the temperature adjustment medium discharged from the assembled battery 1, and transports the temperature adjustment medium from the temperature adjustment circuit 200 to the water jacket 6. The battery temperature sensor 270 is a sensor that detects the internal temperature of the assembled battery 1.

  The vehicle air conditioning system 300 is a circuit that includes a compressor 310, a condenser 320, an evaporator 330, a flow path switching valve 340, a check valve 350, and a refrigerant passage 360 that connects them.

  The compressor 310 is a compressor that compresses the refrigerant, and the compressed refrigerant is sent to the condenser 320. The condenser 320 is a heat exchanger that causes heat exchange between the compressed refrigerant whose temperature has risen and the outside air to lower the temperature of the refrigerant and liquefy the refrigerant. The capacitor 320 is provided with a fan 320F for sending outside air to the capacitor 320 adjacent thereto. The evaporator 330 is a heat exchanger that generates low-temperature air by performing heat exchange between the liquefied refrigerant and the air introduced into the vehicle. Further, the evaporator 330 has a decompression mechanism (not shown). In the vehicle air-conditioning system 300, high-temperature air created by a separate heater (not shown) and this low-temperature air are mixed to create air-conditioning air having a desired temperature and supply it to the vehicle interior. The flow path switching valve 340 has a state in which the refrigerant cooled and liquefied by the condenser 320 is sent only to the evaporator 330, a state in which only the low temperature medium generator 210 is sent, and a state in which both the evaporator 330 and the low temperature medium generator 210 are sent. It is a valve to switch. The check valve 350 is a valve that allows only the flow of the refrigerant from the cold medium generator 210 to the compressor 310 and prevents the refrigerant that has passed through the evaporator 330 from flowing into the cold medium generator 210.

  The control device 260 determines whether or not the assembled battery 1 needs to be cooled and heated based on a signal input from the battery temperature sensor 270.

Specifically, when the control unit 260 determines that the assembled battery 1 needs to be cooled, the control unit 260 switches the flow path switching valve 340 so that the refrigerant is the low temperature medium generator 210 (the evaporator 330 and the low temperature medium during air conditioning). To the generator 210). As a result, the temperature of the temperature control medium decreases, and the assembled battery 1 is cooled by supplying it to the assembled battery 1 with the pump 240. At this time, the control device 260 does not energize the electric heater 220. The control device 260 monitors the temperature of the temperature adjustment medium by the medium temperature sensor 230 and feeds back the load of the vehicle air conditioning system 300 so that the temperature of the temperature adjustment medium is maintained at a temperature suitable for cooling the assembled battery 1. Control. The load of the vehicle air conditioning system 300 is adjusted via a control device (not shown) of the vehicle air conditioning system 300.

  On the contrary, when it is determined that the assembled battery 1 needs to be heated, the control device 260 energizes the electric heater 220 to heat the temperature adjustment medium. And the assembled battery 1 is heated by supplying the heated temperature control medium to the assembled battery 1 with a pump. At this time, the control device 260 switches the flow path switching valve 340 so that the refrigerant does not flow to the low temperature medium generator 210. The control device 260 monitors the temperature of the temperature adjustment medium by the medium temperature sensor 230 and feeds back the energization to the electric heater 220 so that the temperature of the temperature adjustment medium is maintained at a temperature suitable for heating the assembled battery 1. Control.

  FIG. 3 is an explanatory diagram schematically showing the internal structure of the battery module 10. Each battery module 10 is mainly composed of a case 20 and a cell unit 30 accommodated in the case 20. Note that a sheet-like insulator (not shown) is disposed between the case 20 and the cell unit 30 in order to ensure insulation.

  The case 20 is composed of a pair of box bodies 21 having a box shape in which faces facing each other are opened, and the pair of box bodies 21 accommodates the cell unit 30 inside thereof in a state where the opening sides face each other. doing. Output terminals 22 corresponding to the positive electrode and the negative electrode are exposed from a predetermined portion of the case 20 as desired.

  When the case 20 including the pair of box bodies 21 is functionally captured, the case 20 is connected to the side wall portion 20a facing the flat surface of the unit cell 40 and the periphery of the side wall unit 20a, and the unit cell 40 has a thickness direction. And a corresponding peripheral wall portion 20b. The side wall portion 20a constitutes a pair of opposing side walls, and the peripheral wall portion 20b constitutes a square cylinder-shaped peripheral wall. Of the peripheral wall portion 20 b, the peripheral wall portion 20 b on the bottom side facing the floor surface of the vehicle is a thermal connection surface with the water jacket 6.

  The cell unit 30 is configured by electrically connecting a plurality of unit cells 40. Each unit cell 40 has a flat shape and is stacked in the thickness direction.

  FIG. 4 is a perspective view schematically showing the configuration of the unit cell 40. The unit cell 40 is mainly composed of an electrode laminate (not shown) that is a battery element and an exterior member 41 that accommodates the electrode laminate. As the unit cell 40, for example, a lithium ion secondary battery can be used.

  The electrode laminate is configured by alternately laminating positive and negative plates through separators. The positive electrode plate is obtained by applying a positive electrode active material on both sides or one side of a sheet-like positive electrode current collector, and is formed in a substantially square shape. The negative electrode plate is obtained by applying a negative electrode active material to both sides or one side of a sheet-like negative electrode current collector, and is formed in a substantially square shape. The separator is a plate that functions as an ion-permeable insulating layer, and is formed in a substantially square shape.

  The exterior member 41 is composed of a pair of metal composite films (for example, a laminate film in which a synthetic resin layer is laminated on both surfaces of a metal foil). Each metal composite film is a sheet-like member whose outer shape is set to a square shape and has a size slightly larger than that of the electrode laminate, and a concave portion 41a located at the center, and peripheral portions corresponding to the four sides and the periphery thereof 41b. In the pair of metal composite films, the peripheral edge portion 41b is welded so that the peripheral edge portion of the metal composite film is sealed over the entire area, and the electrode laminate is accommodated together with the electrolyte in the space formed by the concave portions 41a.

The end portion of the unit cell 40 includes a peripheral portion 41b and an inclined portion 41c that is located inside the peripheral portion 41b and widens according to the thickness of the contents. The inclined portion 41c has a recess 41a.
Is a part of For the sake of convenience, although not shown in FIG. 4, the unit cell 40 is provided with a sealing portion 48 (see FIG. 3) at the outer peripheral portion of the peripheral portion 41 b in order to improve the sealing performance at the peripheral portion 41 b. ing. The sealing portion 48 has a thickness in the thickness direction of the unit cell 40, and has a function of sealing the outer peripheral portion of the peripheral edge portion 41b.

  Each positive electrode plate is connected to a positive electrode tab 44, and similarly, each negative electrode plate is connected to a negative electrode tab 45. For example, the positive electrode tab 44 and the negative electrode tab 45 are led out from one short side of the exterior member 41 to the outside.

  FIG. 5 is an explanatory diagram schematically showing the unit cell 40 and the heat conducting member 50. As one of the features of the present embodiment, a heat conduction member 50 is disposed in the gap between the peripheral wall portion 20b serving as a bottom surface (that is, a thermal connection surface with the water jacket 6) and the unit cell 40. . The heat conducting member 50 has a function of thermally connecting the peripheral wall portion 20b and the unit cell 40.

  The heat conducting member 50 is provided for each unit cell 40 and is formed so as to cover the end of the unit cell 40. The sealing portion 48 included in the unit cell 40 is also covered with the heat conducting member 50.

  The individual heat conducting members 50 are set to have a thickness corresponding to the unit cell 40. Specifically, since the peripheral portion 41b and the inclined portion 41c are present inside the end portion of the unit cell 40, the heat conduction member 50 has a thickness from the inclined portion 41c to the peripheral portion 41b. The thickness (width in the thickness direction) of the heat conducting member 50 including the peripheral edge portion 41b and the inclined portion 41c and the thickness (width in the thickness direction) of the central portion of the unit cell 40 are set so as to expand. It is set to correspond.

  The heat conducting member 50 is formed of a material having desired heat conductivity and is set to have excellent heat conductivity. Moreover, it is preferable that the heat conductive member 50 is provided with elasticity in addition to heat conductivity, and is preferably composed of an elastic body. As the heat conductive member 50, for example, a resin material or the like can be used. As shown in FIG. 6, the heat conductive member 50 can be formed at the end of the unit cell 40 by filling a mold with a predetermined thermoplastic resin by injection molding. Moreover, as shown in FIG. 7, the heat conductive member 50 can also be formed in the edge part of the cell 40 by predetermined thickness by using a room temperature curable resin material.

  Further, referring to FIG. 4 again, a heat transfer plate 51 (not shown in FIG. 3) is embedded on the surface of the heat conducting member 50. The heat transfer plate 51 is made of a plate material having thermal conductivity, and for example, an aluminum plate can be used. The heat transfer plates 51 are disposed on both the left and right sides of the heat conducting member 50, for example.

  As described above, the battery module 10 according to the present embodiment is disposed in the gap between the peripheral wall portion 21b serving as a connection surface with the water jacket 6 and the single cell 40, and thermally connects the peripheral wall portion 21b and the single cell 40. And a heat conducting member 50 to be connected. The heat conducting member 50 is provided at the end of the unit cell 40 for each unit cell 40 and is set to a thickness corresponding to the unit cell 40.

According to the present embodiment, the heat conducting member 50 provided at the end of the unit cell 40 serves as a heat transfer path between the peripheral wall 21 b serving as a connection surface with the water jacket 6 and the unit cell 40. Thereby, since heat exchange with the water jacket 6 and the cell 40 can be accelerated | stimulated, the temperature control of the battery module 10 can be implement | achieved appropriately. Further, since the heat conducting member 50 has a thickness corresponding to the unit cell 40, the unit cell 40 is not enlarged due to the presence of the heat conducting member 50. Therefore, it is possible to improve the temperature control performance of the battery module 10 by improving the efficiency of heat exchange with the water jacket 6 while suppressing an increase in size of the battery module 10.

  In the present embodiment, the heat conducting member 50 is provided so as to cover the peripheral edge portion 41 b of the exterior member 41. Thereby, the heat conducting member 50 not only serves as a heat transfer path, but also serves to assist the welding force of the peripheral edge portion 41b.

  In the present embodiment, the heat conducting member 50 is provided so as to cover the sealing portion 48. Since this sealing part 48 is the structure which covers the outer peripheral part of the peripheral part 41b, it has thickness in the thickness direction of the cell 40. FIG. Therefore, the heat conduction member 50 is formed so as to include the sealing portion 48, so that the sealing portion 48 and the heat conduction member 50 are engaged with each other. Thereby, it can suppress that the heat conductive member 50 formed in the edge part of the cell 40 falls out in the manufacturing step.

  In the present embodiment, the heat transfer plate 51 is disposed on the left and right side surfaces of the heat conducting member 50. In the configuration in which the sealing portion 48 is provided, the volume of the heat conducting member 50 is reduced as compared with the configuration without this. Therefore, by providing the heat transfer plate 51, even if the sealing portion 48 exists, the heat conduction efficiency by the heat conduction member 50 can be improved.

  Moreover, in this embodiment, the heat conductive member 50 is comprised with the elastic body. According to such a configuration, the heat conducting member 50 present in the gap between the peripheral wall portion 20b and the unit cell 40 functions as a buffer material that absorbs an externally applied impact. Thereby, the vibration of the vehicle can be made difficult to be transmitted to the single battery 40.

  In the present embodiment, the heat conducting member 50 is preferably formed from a room temperature curable resin material. According to such a configuration, there is a merit that there is no possibility of thermally affecting the contents of the unit cell 40 in the manufacturing process in which the heat conduction member 50 is provided on the unit cell 40.

  In the present embodiment, the heat conductive member 50 is provided in a range including the inclined portion 41c and the peripheral portion 41b, and the thickness of the heat conductive member 50 including the inclined portion 41c and the peripheral portion 41b is equal to that of the unit cell 40. Corresponds to the thickness. According to such a configuration, since the thickness does not swell more than that of the unit cell 40, it is possible to suppress the unit cell 40 from being enlarged due to the presence of the heat conductive member 50. Further, when the heat transfer plate 51 is provided, it is preferable that the heat transfer plate 51 is included and corresponds to the thickness of the unit cell 40.

  In the above-described embodiment, the description has been given using the unit cell 40 in which the sealing portion 48 is provided on the outer peripheral portion of the peripheral edge portion 41b. However, as shown in FIG. 8, the heat conducting member 50 may be applied to the unit cell 40 without the sealing portion 48. Thereby, the heat conducting member 50 not only serves as a heat transfer path, but also serves to assist the welding force of the peripheral edge portion 41b. In this case, for example, as shown in FIG. 9, the heat conducting member 50 can be formed at a predetermined thickness at the end of the unit cell 40 by using a room temperature curable resin material. Note that heat transfer plates 51 may be arranged on the left and right side surfaces of the heat conducting member 50.

As described above, the battery module according to the embodiment of the present invention and the assembled battery which is a composite body thereof have been described. However, the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the invention. Needless to say. The application of the battery module and the assembled battery is not limited to an electric vehicle, but is a hybrid vehicle that runs using an electric motor and an internal combustion engine as power sources, and a fuel that runs using an electric motor driven by electric power generated by a fuel cell. It may be a battery vehicle. In addition, the battery module and the assembled battery may be applied to other than the vehicle, and the cell unit may be realized by one single battery. Moreover, although the arrangement | positioning of the temperature control member is set to the bottom face side with respect to the battery module arrange | positioned on a floor surface, it is not limited to this, The other surrounding wall surface (upper surface side, front side, rear surface in a battery module) Even if it is a case where it arrange | positions to the side), the heat conductive member which concerns on this invention can be set corresponding to the thermal connection surface with the temperature control member.

DESCRIPTION OF SYMBOLS 1 assembled battery 5 temperature control apparatus 6 water jacket 10 battery module 20 case 20a side wall part 21b peripheral wall part 30 cell unit 40 single cell 41 exterior member 41a recessed part 41b peripheral part 41c inclined part 48 sealing part 50 heat conduction member 51 heat transfer plate 200 Temperature control circuit

Claims (6)

In a battery module capable of thermally connecting a temperature control member for heating or cooling,
A flat cell,
A single or a plurality of the unit cells, each having a box shape including a side wall portion facing the flat surface of the unit cell and a peripheral wall unit connected to the periphery of the side wall unit and corresponding to the thickness direction of the unit cell. A box-shaped case that is housed inside in a stacked state, and at least a part of the peripheral wall portion is a thermal connection surface with the temperature control member,
A heat conduction member disposed in a gap between the peripheral wall portion serving as the connection surface and the unit cell, and thermally connecting the peripheral wall unit and the unit cell;
The battery module is characterized in that the heat conducting member is provided at an end of the unit cell for each unit cell and is set to a thickness corresponding to the unit cell. The unit cell is configured by welding the peripheral portions of a pair of exterior members that house battery elements therein,
The battery module according to claim 1, wherein the heat conducting member is provided so as to cover a peripheral portion of the exterior member. The unit cell has a sealing part that covers the outer peripheral part of the peripheral part and seals the peripheral part,
The battery module according to claim 2, wherein the heat conducting member is provided so as to cover the sealing portion.   The battery module according to claim 1, wherein the heat conducting member is formed of an elastic body.   The battery module according to any one of claims 1 to 4, wherein the heat conducting member is formed of a room temperature curable resin material. The unit cell includes an inclined portion that widens in accordance with the thickness of the battery element inside the peripheral portion,
The heat conductive member is provided in a range including the inclined portion and the peripheral portion, and the thickness of the heat conductive member including the inclined portion and the peripheral portion corresponds to the thickness of the unit cell. The battery module according to claim 2 or 3, characterized in that

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