Battery Cooling System

Abstract

To provide a battery cooling system capable of efficiently cooling a battery module while miniaturizing a system.SOLUTION: A battery cooling system includes: a battery module in which a plurality of unit cells are stacked; a battery pack in which the battery module is stored; and a cooling unit for cooling the battery module using a refrigerant. The battery module has a first side surface having a terminal unit and a second side surface formed on an opposite side of the first side surface. The cooling unit is not disposed at a position adjacent to the first side surface but disposed adjacent to at least the second side surface.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a battery cooling system. [Background technology]

[0002] Patent Document 1 discloses a vehicle battery pack that houses multiple battery modules. This battery pack is provided with normal cooling piping that is connected to the battery module terminals, and bypass cooling piping that branches off from the normal cooling piping and is arranged to surround each of the multiple battery modules. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-126206 A Summary of the Invention [Problem to be solved by the invention]

[0004] The battery pack described in Patent Document 1 uses a cooling system in which, under normal circumstances, the terminals of the battery modules are cooled by a refrigerant flowing through normal cooling piping, and when necessary, refrigerant is passed through bypass cooling piping to equalize the temperature of multiple battery modules.

[0005] However, when the terminals of the battery module are directly cooled as in the battery pack described in Patent Document 1, insulation measures are required between the terminals and the cooling piping (cooling unit). This makes the battery pack structure complicated and the cooling system large. Furthermore, if an insulator or the like is provided to electrically insulate the terminals from the cooling piping, the heat transfer from the terminals is also blocked, which may reduce the cooling efficiency.

[0006] The present invention has been made in consideration of the above problems, and has an object to provide a battery cooling system that can efficiently cool battery modules while miniaturizing the system. [Means for solving the problem]

[0007] According to one aspect of the present invention, a battery module formed by stacking a plurality of unit cells; Multiple A battery cooling system is provided, comprising a battery pack that houses a battery module and a cooling unit that cools the battery module using a refrigerant. The battery module has a first side surface that includes a terminal portion and a second side surface that is formed on the opposite side to the first side surface, and the cooling unit is not disposed in a position adjacent to the first side surface, but is disposed at least adjacent to the second side surface. The multiple battery modules are arranged such that their first sides face inward within the battery pack and their second sides are adjacent to an inner circumferential surface of the battery pack, and the cooling unit is formed to pass between the second sides of the multiple battery modules and the inner circumferential surface of the battery pack and surround the multiple battery modules. Effect of the Invention

[0008] According to the battery cooling system of the present invention, the cooling unit is not disposed adjacent to a first side surface of the battery module having a terminal portion, but is disposed adjacent to a second side surface opposite to the first side surface. Therefore, insulation measures between the cooling unit and the terminal portion of the battery module are not required, and the structure of the battery cooling system can be simplified. In addition, since there is no need to provide an insulator or the like between the cooling unit and the battery module, heat transfer from the battery module is not blocked, and the battery module can be cooled efficiently. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing the main configuration of a battery cooling system according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along the line AA in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line BB in FIG. [Figure 4] FIG. 4 is a schematic configuration diagram of a battery cooling system according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] (First embodiment) 1 is a schematic diagram showing the main configuration of a battery cooling system 100 according to a first embodiment. The battery cooling system 100 is mounted on, for example, a vehicle.

[0012] As shown in Fig. 1, the battery cooling system 100 includes a battery pack 1, a plurality of battery modules 10 housed in the battery pack 1, and a cooling unit 20 that cools the battery modules 10. Fig. 1 is a cross-sectional view of the battery pack 1 as viewed from above.

[0013] The battery module 10 is formed by stacking a plurality of flat unit cells (single cells) 11 (see FIG. 2), and the battery pack 1 is formed by housing a plurality of the battery modules 10.

[0014] The multiple battery modules 10 housed in the battery pack 1 include a first battery module group 12 consisting of multiple battery modules 10a arranged in series, and a second battery module group 13 consisting of multiple battery modules 10b arranged in series. The first battery module group 12 and the second battery module group 13 are arranged in parallel and symmetrically in the battery pack 1. The direction of the arrow in Fig. 1 is the front-rear direction of the vehicle in which the battery cooling system 100 is mounted, and the first battery module group 12 and the second battery module group 13 are arranged symmetrically in the left-right direction (width direction) of the vehicle.

[0015] Moreover, each battery module 10 in the battery pack 1 has a terminal portion 14 on one side surface (first side surface) 101, and the side surfaces 101 having the terminal portion 14 all face inward within the battery pack 1. Meanwhile, the side surface (second side surface) 102 opposite the first side surface 101 of each battery module 10 is close to the inner peripheral surface of the battery pack 1. Since all first side surfaces 101 having the terminal portion 14 face inward within the battery pack 1 in this manner, various wirings connected to the terminal portion 14 can be concentrated in the center of the battery pack 1.

[0016] The cooling unit 20 is a cooling plate provided at a position adjacent to the second side surface 102 of the battery module 10. The cooling unit 20 has a refrigerant flow path 21 (see FIG. 2) therein, and cools the battery module 10 using a refrigerant flowing through the refrigerant flow path 21. The cooling unit 20 passes between the second side surface 102 of each battery module 10 and the inner circumferential surface of the battery pack 1, and is formed in an annular shape along the inner circumferential surface of the battery pack 1 so as to surround all of the multiple battery modules 10 in the battery pack 1.

[0017] As described above, in the battery cooling system 100, the battery module 10 is cooled by the cooling unit 20 provided at a position adjacent to the battery module 10.

[0018] Incidentally, the first side surface 101 of the battery module 10, which includes the terminal portion 14, is likely to be the hottest. Therefore, in order to increase the cooling efficiency, it is conceivable to provide the cooling unit 20 at a position adjacent to the first side surface 101 and directly cool the terminal portion 14. However, when the terminal portion 14 is directly cooled by the cooling unit 20, it is necessary to electrically insulate the terminal portion 14 from the cooling unit 20. Therefore, the structure of the battery pack 1 may become complicated due to the insulation measures, and the battery cooling system 100 may become large. In addition, if an insulator or the like is provided to electrically insulate the terminal portion 14 from the cooling unit 20, the heat transfer from the terminal portion 14 to the cooling unit 20 may also be blocked, and the cooling efficiency may be reduced. In contrast, in this embodiment, as described above, the cooling unit 20 is provided at a position adjacent to the second side surface 102 opposite to the first side surface 101 including the terminal portion 14. Therefore, since insulation measures between the cooling unit 20 and the terminal portion 14 of the battery module 10 are not required, the structure of the battery cooling system 100 may be simplified. Furthermore, since there is no need to provide an insulator or the like between the cooling unit 20 and the battery module 10, heat transfer from the battery module 10 is not blocked, and the battery module 10 can be cooled efficiently.

[0019] FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, and is a diagram illustrating the cooling structure of the battery module 10. As shown in FIG.

[0020] 2, the battery module 10 includes a plurality of stacked unit cells 11 and a heat dissipation plate 15 provided between adjacent unit cells 11. In addition, support plates 30 that support the battery module 10 are provided at upper and lower ends in the stacking direction of the unit cells 11 in the battery module 10.

[0021] The heat dissipation plate 15 is a member that dissipates heat generated in the unit cells 11, and is made of aluminum, copper alloy, or the like having thermal conductivity. The heat dissipation plate 15 is sandwiched between adjacent unit cells 11. The heat dissipation plate 15 also has a heat dissipation portion 151 that extends upward and downward in the stacking direction of the unit cells 11 along the second side surface 102 of the battery module 10. The heat dissipation portion 151 of the heat dissipation plate 15 is in contact with one side of the cooling unit (cooling plate) 20 via the heat spreader sheet 40 and the heat spreader plate 50.

[0022] The heat spreader sheet 40 and the heat spreader plate 50 are interposed between the battery module 10 (heat dissipation plate 15) and the cooling unit 20. The heat spreader sheet 40 is made of a thermally conductive material such as an acrylic or silicone material, and improves the heat transfer from the heat dissipation plate 15 while diffusing the heat evenly. The heat spreader sheet 40 also improves the adhesion between the heat dissipation plate 15 and the cooling unit 20. The heat spreader plate 50 is made of a thermally conductive material such as aluminum or copper alloy, and improves the heat transfer from the heat dissipation plate 15 while improving the adhesion between the heat dissipation plate 15 and the cooling unit 20.

[0023] The cooling unit 20 is a cooling plate having a plurality of refrigerant flow paths 21 through which a refrigerant flows, and is provided at a position adjacent to the second side surface 102 of the battery module 10. One surface of the cooling unit 20 contacts the heat dissipation portion 151 of the heat dissipation plate 15 via the heat spreader sheet 40 and the heat spreader plate 50. The surface (the other surface) of the cooling unit 20 opposite to the surface contacting the heat dissipation plate 15 is pressed toward the heat dissipation portion 151 of the heat dissipation plate 15 by a pressing plate 60 fastened to the support plate 30 provided at the upper end of the battery module 10 and the bottom surface of the battery pack 1. The amount of refrigerant flowing through the refrigerant flow paths 21 is controlled by a controller (not shown) or the like.

[0024] With the above configuration, heat from the battery module 10 is transferred from the heat dissipation plate 15 through the heat spreader sheet 40 and the heat spreader plate 50 to the cooling unit 20 adjacent to the second side surface 102 of the battery module 10. This allows heat exchange between the battery module 10 and the cooling unit 20, and the battery module 10 is cooled.

[0025] As described above, in this embodiment, the cooling unit 20 is disposed at a position adjacent to the second side surface 102 opposite to the first side surface 101 having the terminal portion 14 of the battery module 10, and is not disposed at a position adjacent to the first side surface 101. Therefore, insulation measures between the cooling unit 20 and the terminal portion 14 of the battery module 10 are not required, and the structure of the battery cooling system 100 can be simplified. Also, since there is no need to provide an insulator or the like between the cooling unit 20 and the battery module 10, heat transfer from the battery module 10 is not blocked, and the battery module 10 can be efficiently cooled.

[0026] Furthermore, when the cooling unit 20 is provided at a position in contact with the bottom surface of the battery module 10 (on the bottom side), it is necessary to control the amount of pressure that the cooling unit 20 presses against the battery module 10, taking into account the weight of the battery module 10. In contrast, in this embodiment, the cooling unit 20 is provided at a position adjacent to the side surface 102 of the battery module 10, so there is no need to take into account the weight of the battery module 10 when controlling the amount of pressure with which the cooling unit 20 presses against the battery module 10 (heat dissipation plate 15). Therefore, it is easier to control the amount of pressure that the cooling unit 20 presses against the battery module 10, compared to when the cooling unit 20 is provided at a position in contact with the bottom surface of the battery module 10.

[0027] Furthermore, if the cooling unit 20 is provided on the bottom side of the battery module 10, condensed water is likely to accumulate between the battery module 10 and the cooling unit 20, and there is a risk that the condensed water will adhere to the battery module 10. In contrast, in this embodiment, the cooling unit 20 is provided at a position adjacent to the second side surface 102 of the battery module 10, so that the condensed water falls onto the bottom surface of the battery pack 1 and does not adhere to the battery module 10. Furthermore, since the cooling unit 20 is provided at a position adjacent to the second side surface 102 that is distant from the terminal portion 14, even if condensed water occurs, it will not adhere to the terminal portion 14. Therefore, the electrical insulation between the battery module 10 and the cooling unit 20 is prevented from being deteriorated due to condensation.

[0028] FIG. 3 is a cross-sectional view taken along line BB in FIG. 1, and is a diagram for explaining convection in the battery pack 1. As shown in FIG.

[0029] As described above, each battery module 10 in the battery pack 1 has a first side surface 101 including a terminal portion 14 facing inward within the battery pack 1, and a second side surface 102 opposite to the first side surface 101 is adjacent to the inner circumferential surface of the battery pack 1 (see FIG. 1). The cooling unit 20 is disposed adjacent to the second side surface 102 of the battery module 10, passes between the second side surface 102 of the battery module 10 and the inner circumferential surface of the battery pack 1, and is formed along the inner circumferential surface of the battery pack 1 so as to surround all of the battery modules 10 in the battery pack 1 (see FIG. 1).

[0030] Here, the temperature of the first side surface 101 of the battery module 10, which includes the terminal portion 14, is relatively higher than that of the second side surface 102 adjacent to the cooling unit 20. That is, a temperature difference occurs between one side surface 101 (terminal portion 14 side) and the other side surface 102 (cooling unit 20 side) of the battery module 10. Due to this temperature difference, the high-temperature air on the terminal portion 14 side flows from the upper portion of the battery module 10 to the cooling unit 20 side, and the low-temperature air on the cooling unit 20 side flows from the lower portion of the battery module 10 to the terminal portion 14 side. As a result, as shown by the arrows in FIG. 3, a convection current of air circulating between the terminal portion 14 side and the cooling unit 20 side is generated so as to surround the battery module 10. In addition, since each battery module 10 is arranged so that the terminal portion 14 side faces inward in the battery pack 1, a convection current circulating between the center and the periphery of the battery pack 1 is generated throughout the entire battery pack 1, and the amount of heat dissipated by each battery module 10 increases. That is, this improves the cooling efficiency of the battery module 10. In contrast, if the cooling unit 20 is disposed on the terminal portion 14 side or bottom side of the battery module 10, for example, convection surrounding the battery module 10 does not occur.

[0031] Furthermore, since the cooling unit 20 is formed along the inner circumferential surface of the battery pack 1 so as to surround the entirety of the multiple battery modules 10 in the battery pack 1 (see FIG. 1), even if there is a heat source outside the battery pack 1, the heat from the heat source reaches the battery modules 10 through the cooling unit 20. In other words, since the heat from the heat source is not directly received by the battery modules 10, the impact of the heat from the heat source on the battery modules 10 is reduced. For example, if a heat source such as an engine exhaust pipe is installed outside the battery pack 1, the heat from the heat source is cooled by the cooling unit 20 before it reaches the battery modules 10, and the impact of the heat from the heat source on the battery modules 10 is reduced.

[0032] In addition, since the cooling unit 20 is formed along the inner circumferential surface of the battery pack 1 so as to surround the entirety of the multiple battery modules 10 in the battery pack 1 (see FIG. 1), even if an external force is applied to the side surface 101 of the battery pack 1, the cooling unit 20 acts as a buffer material and reduces the impact on the battery modules 10. For example, even if an external force is applied to the battery pack 1 during a collision of a vehicle equipped with the battery pack 1, the external force is reduced by the cooling unit 20, so that the external force is prevented from being directly input to the battery modules 10, and the impact of the external force on the battery modules 10 is reduced. In addition, since the battery modules 10 are arranged so that the terminal portions 14 face the inside of the battery pack 1, even if an external force is applied to the side surface of the battery pack 1, the external force is prevented from being directly input to the terminal portions 14, and the impact of the external force on the battery modules 10 is further reduced.

[0033] Furthermore, since the cooling unit 20 is formed to surround all of the multiple battery modules 10 in the battery pack 1 (see FIG. 1), the battery cooling system 100 can be made more compact than in the case of providing the cooling unit 20 with bypass cooling piping that surrounds each battery module 10, as in Patent Document 1.

[0034] As mentioned above, in the battery module 10, the temperature on the terminal portion 14 side is relatively higher than that on the cooling unit 20 side. However, since the heat dissipation plate 15 is sandwiched between adjacent single cells 11 and the heat dissipation plate 15 is in contact with the cooling unit 20 via the heat spreader sheet 40 and the heat spreader plate 50, the single cells 11 can be uniformly cooled.

[0035] According to the battery cooling system 100 of the first embodiment described above, the following effects can be obtained.

[0036] In the battery cooling system 100, the cooling unit 20 is not disposed at a position adjacent to the first side surface 101 of the battery module 10 having the terminal portion 14, but is disposed adjacent to the second side surface 102 opposite to the first side surface 101. Therefore, insulation measures between the cooling unit 20 and the terminal portion 14 of the battery module 10 are not required, and the structure of the battery cooling system 100 can be simplified. Also, since there is no need to provide an insulator or the like between the cooling unit 20 and the battery module 10, heat transfer from the battery module 10 is not blocked, and the battery module 10 can be efficiently cooled. That is, the battery module 10 can be efficiently cooled while the battery cooling system 10 is miniaturized.

[0037] In addition, because the cooling unit 20 is disposed at a position adjacent to the second side surface 102 of the battery module 10, there is no need to take into consideration the weight of the battery module 10 when controlling the amount of pressure with which the cooling unit 20 is pressed against the battery module 10. Therefore, it is easier to control the amount of pressure of the cooling unit 20 compared to when the cooling unit 20 is provided on the bottom side of the battery module 10.

[0038] In addition, because the cooling unit 20 is disposed adjacent to the second side surface 102 of the battery module 10, condensed water falls onto the bottom surface of the battery pack 1 and does not adhere to the battery module 10. In addition, because the cooling unit 20 is disposed adjacent to the second side surface 102 away from the terminal portion 14, even if condensed water occurs, it does not adhere to the terminal portion 14. This prevents the electrical insulation between the battery module 10 from being deteriorated due to condensation.

[0039] In the battery cooling system 100, a battery pack 1 houses a plurality of battery modules 10, and all the battery modules 10 in the battery pack 1 are arranged so that a first side surface 101 (terminal portion 14 side) faces inward in the battery pack 1. In this manner, since each battery module 10 is arranged so that the terminal portion 14 side faces inward in the battery pack 1, convection occurs throughout the battery pack 1 due to a temperature difference between the terminal portion 14 side and a second side surface 102 (cooling unit 20 side) to which the cooling unit 20 is adjacent. That is, convection occurs throughout the battery pack 1, circulating between the center and the periphery of the battery pack 1. This increases the amount of heat dissipated by each battery module 10, improving the cooling efficiency of the battery module 10.

[0040] In addition, the battery module 10 is arranged so that the first side surface 101 (terminal portion 14 side) faces the inside of the battery pack 1. Therefore, even if an external force is applied to the side surface of the battery pack 1, the external force is prevented from being directly input to the terminal portion 14, and the effect of the external force on the battery module 10 is reduced.

[0041] In the battery cooling system 100, a battery pack 1 houses a plurality of battery modules 10, and a cooling unit 20 is formed so as to pass between the second side surface 102 of each battery module 10 and the inner peripheral surface of the battery pack 1 and to surround all of the plurality of battery modules 10 in the battery pack 1. Therefore, even if a heat source such as an engine exhaust pipe is installed outside the battery pack 1, heat from the heat source reaches the battery module 10 through the cooling unit 20 and is not directly received by the battery module 10. Therefore, the effect of heat from the heat source outside the battery pack 1 on the battery module 10 is reduced.

[0042] In addition, since the cooling unit 20 is formed to surround all of the multiple battery modules 10 in the battery pack 1, even if an external force is applied to the side of the battery pack 1, the cooling unit 20 acts as a cushioning material, further reducing the impact on the battery modules 10.

[0043] Furthermore, since the cooling unit 20 is formed to surround all of the multiple battery modules 10 in the battery pack 1, the battery cooling system 100 can be made more compact than in the case where the cooling unit 20 is provided with bypass piping surrounding each battery module 10.

[0044] The battery cooling system 100 houses a first battery module group 12, which is composed of a plurality of battery modules 10a arranged in series, and a second battery module group 13, which is composed of a plurality of battery modules 10b arranged in series and arranged in parallel with the first battery module group 12. Each battery module 10 is arranged so that a first side surface 101 faces inward in the battery pack 1 and a second side surface 102 is close to the inner circumferential surface of the battery pack 1. In this way, each battery module constituting the battery module groups 12 and 13 arranged in series has a first side surface 101 having a terminal portion 14 facing inward of the battery pack 1, so that various wirings connected to the terminal portion 14 can be concentrated in the center of the battery pack 1. That is, the configuration inside the battery pack 1 can be simplified.

[0045] In the present embodiment, eight battery modules 10 are arranged in the battery pack 1 in FIG. 1, however, the number of battery modules 10 is not limited to this, and any number of battery modules 10 may be arranged in the battery pack 1.

[0046] In order to reduce the influence of heat and external forces from the outside of the battery pack 1, it is preferable that the terminals 14 of all the battery modules 10 face the inside of the battery pack 1 and the cooling units 20 are arranged along the inner circumferential surface of the battery pack 1, but this is not necessarily limited to this. For example, the cooling units 20 of all the battery modules 10 may face the inside of the battery pack 1 and the terminals 14 face the inner circumferential surface of the battery pack 1. Even in this case, convection circulating between the center and the periphery of the battery pack 1 occurs throughout the battery pack 1 due to the temperature difference between the terminals 14 and the cooling units 20 of the battery modules 10, so that the amount of heat dissipated by each battery module 10 increases and the cooling efficiency of the battery module 10 is further improved. Even in this case, the cooling units 20 can be formed in a ring shape along the second side surface 102 of each battery module 10, so that the battery cooling system 100 can be made more compact than when a bypass piping is provided.

[0047] Furthermore, for example, the orientation of the terminal portion 14 side and the cooling unit 20 side of each battery module 10 may be different. Even in this case, if the cooling unit 20 is disposed adjacent to the second side surface 102 of the battery module 10, insulation measures between the cooling unit 20 and the terminal portion 14 of the battery module 10 are not required, so that the battery cooling system 100 can be made compact while efficiently cooling the battery module 10.

[0048] In addition, in this embodiment, the first and second battery module groups 12, 13, each composed of a plurality of battery modules 10 arranged in series, are arranged in parallel and symmetrically, but this is not necessarily limited to this. As described above, if the cooling unit 20 is arranged adjacent to the second side surface 102 of the battery module 10, it is possible to obtain the effect of efficiently cooling the battery module 10 while miniaturizing the battery cooling system 100.

[0049] In this way, the number of battery modules 10 is arbitrary, and the battery modules 10 may be arranged in any position within the battery pack 1.

[0050] In the present embodiment, the cooling unit 20 is disposed only at a position adjacent to the second side surface 102 of the battery module 10, but this is not necessarily limited to this. That is, the cooling unit 20 may be provided at a position adjacent to the bottom surface or the top surface of the battery module 10 in addition to a position adjacent to the second side surface 102 of the battery module 10. However, the cooling unit 20 is not disposed at a position adjacent to the side surface 101 having the terminal portion 14.

[0051] In addition, in the present embodiment, one surface of the cooling unit 20 is in contact with the heat dissipation portion 151 of the heat dissipation plate 15 via the heat spreader sheet 40 and the heat spreader plate 50, but this is not necessarily limited to the configuration. As for the cooling structure of the battery module 10, as long as the cooling unit 20 is disposed adjacent to at least the second side surface 102 of the battery module 10 and is not disposed in a position adjacent to the first side surface 101, other configurations are arbitrary, and any known cooling structure may be used.

[0052] In addition, in the present embodiment, in Figs. 2 and 3, five unit cells 11 are stacked to form the battery module 10, but the number of stacked unit cells 11 is not limited to this, and any number of unit cells may be stacked.

[0053] Second embodiment A battery cooling system 100 according to a second embodiment will be described with reference to Fig. 4. Note that the same elements as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0054] 4 is a schematic configuration diagram of a battery cooling system 100 according to a second embodiment. This embodiment differs from the first embodiment in that the cooling unit 20 includes a first cooling unit 20a and a second cooling unit 20b.

[0055] 4, in this embodiment, the cooling unit 20 branches into a first cooling unit 20a and a second cooling unit 20b at a branch point 22 outside the battery pack 1. The first cooling unit 20a and the second cooling unit 20b are arranged symmetrically within the battery pack 1.

[0056] The first cooling unit 20a is a cooling plate that cools the multiple battery modules 10a that constitute the first battery module group 12 using a refrigerant flowing through a refrigerant flow path 21 (see FIG. 2). The first cooling unit 20a is disposed adjacent to the second side surface 102 of each battery module 10a that constitutes the first battery module group 12, and passes between the second side surface 102 of each battery module 10a that constitutes the first battery module group 12 and the inner circumferential surface of the battery pack 1.

[0057] The second cooling unit 20b is a cooling plate that cools the multiple battery modules 10b that constitute the second battery module group 13 using a refrigerant flowing through a refrigerant flow path 21 (see FIG. 2). The second cooling unit 20b is disposed adjacent to the second side surface 102 of each battery module 10b that constitutes the second battery module group 13, and passes between the second side surface 102 of each battery module 10b that constitutes the second battery module group 13 and the inner circumferential surface of the battery pack 1.

[0058] In this manner, the cooling unit 20 that cools the battery modules 10 is branched into the first and second cooling units 20a, 20b, thereby reducing the temperature difference between the upstream and downstream sides of the cooling unit 20. That is, the cooling efficiency of the battery modules 10 is improved, and the temperature variation between the battery modules 10 is reduced.

[0059] In addition, the first cooling unit 20a and the second cooling unit 20b are arranged symmetrically within the battery pack 1, so that the battery modules 10a constituting the first battery module group 12 and the battery modules 10b constituting the second battery module group 13 are evenly cooled. Therefore, the temperature variation between the battery modules 10 is further reduced.

[0060] In this embodiment, the cooling unit 20 is configured to branch at the branch point 22 outside the battery pack 1, but this is not necessarily limited to this, and the cooling unit 20 may be configured to branch inside the battery pack 1. Also, instead of the cooling unit 20 branching, a structure may be adopted in which two different cooling units are provided to cool the battery module 10a constituting the first battery module group 12 and the battery module 10b constituting the second battery module group 13, respectively.

[0061] In order to further reduce the temperature variation between the battery modules 10, it is preferable to arrange the first cooling unit 20a and the second cooling unit 20b symmetrically in the battery pack 1 as in this embodiment, but this is not necessarily limited to this. That is, as long as the cooling unit 20 is branched or has two different cooling units, it is possible to obtain the effects of improving the cooling efficiency of the battery modules 10 and reducing the temperature variation between the battery modules 10 even if the first cooling unit 20a and the second cooling unit 20b are not arranged symmetrically.

[0062] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above-mentioned embodiments.

[0063] Although the above-described embodiments have been described as separate embodiments, they may be combined as appropriate. [Explanation of symbols]

[0064] 1 Battery pack 10 Battery module 11 Single cell 14 Terminal section 20 Cooling Unit 100 Battery Cooling System 101 First Aspect 102 The Second Aspect

Claims

1. A battery module formed by stacking a plurality of unit cells; a battery pack that houses a plurality of the battery modules; a cooling unit that cools the battery module using a refrigerant; A battery cooling system comprising: the battery module has a first side surface having a terminal portion and a second side surface formed on an opposite side to the first side surface; the cooling unit is not disposed adjacent to the first side surface, and is disposed adjacent to at least the second side surface; the plurality of battery modules are arranged such that the first side surfaces face inward within the battery pack and the second side surfaces are adjacent to an inner circumferential surface of the battery pack; the cooling unit is formed so as to pass between the second side surfaces of the plurality of battery modules and an inner peripheral surface of the battery pack and surround the plurality of battery modules. Battery cooling system.

2. 2. The battery cooling system of claim 1, the battery modules in the battery pack are arranged such that all of the first side surfaces or all of the second side surfaces face inward within the battery pack; Battery cooling system.

3. A battery module formed by stacking a plurality of unit cells; a battery pack that houses the battery module; a cooling unit that cools the battery module using a refrigerant; A battery cooling system comprising: the battery module has a first side surface having a terminal portion and a second side surface formed on an opposite side to the first side surface; the cooling unit is not disposed adjacent to the first side surface, and is disposed adjacent to at least the second side surface; the battery pack houses a first battery module group composed of a plurality of the battery modules arranged in series, and a second battery module group composed of a plurality of the battery modules arranged in series and arranged in parallel with the first battery module group; the battery modules constituting the first battery module group and the second battery module group are arranged such that the first side surfaces face inward within the battery pack and the second side surfaces are adjacent to an inner circumferential surface of the battery pack; the cooling units include a first cooling unit that cools the battery modules constituting the first battery module group and a second cooling unit that cools the battery modules constituting the second battery module group; the first cooling unit passes between the second side surface of each battery module constituting the first battery module group and an inner circumferential surface of the battery pack, the second cooling unit passes between the second side surface of each battery module constituting the second battery module group and an inner peripheral surface of the battery pack. Battery cooling system.

4. A battery cooling system as described in claim 3, the first battery module group and the second battery module group are arranged symmetrically within the battery pack; the cooling unit has a branch point where the cooling unit branches into the first cooling unit and the second cooling unit, the first cooling unit and the second cooling unit are disposed symmetrically within the battery pack; Battery cooling system.

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