Battery pack

Abstract

To uniformly cool a plurality of cells included in a battery pack.SOLUTION: A battery pack 10 includes: a plurality of cells 20 which each have a pair of wide faces 21 facing each other; a support member 40 supporting the cells 20; a U-turn flow path forming member 60; and a refrigerant supply device 80. The support member 40 disposes the cells 20 with an interval therebetween while the wide faces 21 face each other. The support member 40 includes, between each pair of adjacent cells 20 among the cells 20, a first flow path 51 from a first side 21a to a second side 21b of the wide face 21 in a width direction D2; and a second flow path 52 from the second side 21b to the first side 21a, the second flow path being independent from the first flow path 51. The U-turn flow path forming member 60 is disposed on the second side 21b of the wide face 21 of the cells 20, and has a third flow path 53 connecting the first flow path 51 and the second flow path 52. The refrigerant supply device 80 is constituted to supply a refrigerant from the first side 21a of the first flow path 51.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] For example, JP 2015-72741 A discloses a battery pack having a function of cooling batteries. The battery pack includes a housing that houses multiple batteries, a fluid drive means that circulates a fluid that cools the multiple batteries within the housing, a circulation passage formed inside the housing for returning the fluid to the fluid drive means after heat exchange with the multiple batteries, and a Peltier module that absorbs heat from the fluid.

[0003] The fluid discharged from the fluid driving means passes through the batteries and absorbs heat from the batteries, thereby cooling the batteries housed in the housing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-72741 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the battery pack disclosed in JP 2015-72741 A, the fluid passes through the battery in one direction from top to bottom, which causes a temperature difference between the fluid inlet and outlet of the battery, which may make it difficult to cool the entire battery uniformly. [Means for solving the problem]

[0006] The battery pack disclosed herein includes a plurality of cells each having a pair of wide surfaces facing each other, a support member supporting the plurality of cells, a U-turn flow path forming member, and a coolant supply device. The support member is configured to arrange the plurality of cells with the wide surfaces facing each other with a gap therebetween. The support member has a first flow path between adjacent cells among the plurality of cells, the first flow path extending from a first side to a second side in the width direction of the wide surfaces, and a second flow path independent of the first flow path and extending from the second side to the first side. The U-turn flow path forming member is arranged on the second side of the wide surfaces of the plurality of cells, and has a third flow path connecting the first flow path and the second flow path. The coolant supply device is configured to supply a coolant from the first side of the first flow path.

[0007] According to the battery pack, the coolant supplied from the coolant supply device passes through the first flow path, thereby cooling the portion of the cell located around the first flow path. The coolant that passes through the first flow path and reaches the third flow path passes through the second flow path, thereby cooling the portion of the cell located around the second flow path. Thus, the entire cell can be cooled by the coolant passing through the first and second flow paths. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a battery pack according to an embodiment. [Diagram 2] FIG. 2 is a plan view showing the battery pack according to the embodiment. [Diagram 3] 3 is a cross-sectional view of the battery pack taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a front view showing a support member supporting a plurality of cells. [Diagram 5] FIG. 4 is a front view showing a U-turn flow path forming member. [Figure 6] FIG. 13 is a front view showing a support member of a battery pack according to another embodiment. [Figure 7] FIG. 5 is a cross-sectional view showing a battery pack according to another embodiment, which is equivalent to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the technology disclosed herein will be described with reference to the drawings. Note that the embodiment described herein is not intended to limit the invention described in the claims of this application. Each drawing is drawn typically and does not necessarily faithfully reflect an actual embodiment. Furthermore, the same reference numerals are appropriately used for components and parts that perform the same function, and duplicated explanations are appropriately omitted.

[0010] 1 and 2 are a perspective view and a plan view, respectively, showing a battery pack 10 according to this embodiment. FIG. 3 is a cross-sectional view of the battery pack 10 taken along line III-III in FIG. 2. In the drawings, the symbols F, Rr, L, R, U, and D indicate the front, rear, left, right, top, and bottom of the battery pack 10, respectively. The symbols D1, D2, and D3 indicate the first direction, the second direction, and the third direction, respectively. Here, the first direction D1, the second direction D2, and the third direction D3 intersect with each other (here, they are perpendicular). In this embodiment, the first direction D1 is the left-right direction. The second direction D2 is the front-rear direction. The third direction D3 is the up-down direction. However, these directions are merely defined for the convenience of explanation and should not be interpreted in a restrictive manner.

[0011] 1, the battery pack 10 according to this embodiment is composed of a plurality of cells 20 and is capable of being charged and discharged. The battery pack 10 includes the plurality of cells 20, a support member 40, a U-turn flow path forming member 60, a cooling device 70, and a refrigerant supply device 80.

[0012] The cell 20 is chargeable and dischargeable. For example, the cell 20 is a secondary battery that can be repeatedly charged and discharged by the movement of charge carriers between a pair of electrodes (for example, a positive electrode and a negative electrode) via an electrolyte. The cell 20 can be, for example, a lithium ion secondary battery, a nickel-metal hydride battery, or the like.

[0013] The number of cells 20 constituting the battery pack 10 is not particularly limited, and is a predetermined number. In the present embodiment, a case where the number of cells 20 is four will be described as an example. The configuration of the cells 20 is not particularly limited. The cells 20 have, for example, a rectangular parallelepiped shape. Here, as shown in FIG. 2, the cells 20 have a shape that is longer in the second direction D2 than in the first direction D1. The cells 20 have a pair of opposing wide faces 21 and a pair of opposing narrow faces 22. The pair of wide faces 21 face each other along the first direction D1. The wide faces 21 extend in the second direction D2 and the third direction D3. The pair of narrow faces 22 face each other along the second direction D2. The narrow faces 22 extend in the first direction D1 and the third direction D3. Here, the narrow faces 22 are arranged so as to be perpendicular to the wide faces 21 in a plan view. The wide faces 21 have a larger area than the narrow faces 22. Although not shown in the figure, the cell 20 has, for example, a case, an electrode assembly housed in the case, and an electrolyte housed in the case. The electrode assembly is stacked or wound in the case. The wide surface 21 and narrow surface 22 of the cell 20 are formed by the case.

[0014] In this embodiment, the width direction of the wide surface 21 refers to the second direction D2, i.e., the front-rear direction. One end side of the wide surface 21 of the cell 20 in the width direction (second direction D2) is referred to as the first side 21a, and the other end side in the width direction is referred to as the second side 21b. Here, the first side 21a is the front side in the second direction D2. The second side 21b is the rear side in the second direction D2.

[0015] In the battery pack 10, the multiple cells 20 are arranged side by side in the first direction D1. The multiple cells 20 are stacked in the first direction D1. Here, the multiple cells 20 are arranged with the wide surfaces 21 of adjacent cells 20 facing each other. The multiple cells 20 are arranged with a gap between them. That is, the facing wide surfaces 21 of adjacent cells 20 are spaced apart and do not contact each other.

[0016] As shown in FIG. 1, the support member 40 is a member that supports the multiple cells 20. Here, as shown in FIG. 2, the support member 40 supports the multiple cells 20 by maintaining the posture of the multiple cells 20 arranged with the wide surfaces 21 facing each other while leaving a gap between the multiple cells 20 in the first direction D1. The support member 40 fixes the positions of the multiple cells 20 while maintaining the gap between the multiple cells 20. In this embodiment, the support member 40 has a rectangular parallelepiped shape, but the shape of the support member 40 is not particularly limited. In addition, the material forming the support member 40 is not particularly limited. Here, the support member 40 is made of resin, for example, polypropylene.

[0017] Further, the configuration in which the support member 40 supports the multiple cells 20 is not particularly limited. In the present embodiment, the support member 40 has multiple support holes 42 formed therein. The cells 20 are inserted into the support holes 42. The support holes 42 are holes that support the cells 20 in a state in which the cells 20 are accommodated. One cell 20 is accommodated in one support hole 42. The support holes 42 are formed in the upper surface of the support member 40 and are holes formed downward from the upper surface. The support holes 42 extend in the third direction D3, i.e., the up-down direction. The cells 20 are accommodated and supported in the support holes 42 from above the support member 40. The support holes 42 have a rectangular shape in a plan view, similar to the cells 20. The number of the support holes 42 is the same as the number of the cells 20 that constitute the battery pack 10. Here, the multiple support holes 42 are aligned in the first direction D1, and adjacent support holes 42 are spaced apart at a predetermined interval. In this embodiment, the multiple cells 20 can be arranged side by side along the first direction D1 with a gap therebetween by being accommodated in the support holes 42. Note that, here, as shown in Fig. 1, when the cells 20 are accommodated in the support holes 42, the upper ends of the cells 20 may be exposed upward. In this embodiment, in a state in which the cells 20 are inserted and supported in the support holes 42, the support member 40 is configured to restrain the cells 20 with a predetermined restraining pressure.

[0018] FIG. 4 is a front view showing a support member 40 supporting a plurality of cells 20. In this embodiment, as shown in FIG. 4, the support member 40 has a first flow path 51 and a second flow path 52. As shown in FIG. 3, a refrigerant, which will be described later, supplied from a refrigerant supply device 80 passes through the first flow path 51 and the second flow path 52. The first flow path 51 and the second flow path 52 are formed in the support member 40 along the second direction D2. The first flow path 51 and the second flow path 52 are flow paths that penetrate the support member 40 in the second direction D2. The first flow path 51 is a flow path that extends from the first side 21a to the second side 21b of the wide surface 21 in the second direction D2. The second flow path 52 is independent of the first flow path 51 and is a flow path that extends from the second side 21b to the first side 21a of the wide surface 21. Here, the first flow path 51 and the second flow path 52 extend linearly, but may be at least partially curved.

[0019] As shown in Fig. 4, both the first flow paths 51 and the second flow paths 52 are provided between adjacent cells 20 (in other words, adjacent support holes 42) among the multiple cells 20. Therefore, there are multiple first flow paths 51, and there are also multiple second flow paths 52. The number of first flow paths 51 is the same as the number of second flow paths 52. Here, the multiple first flow paths 51 are arranged side by side in the first direction D1. The multiple second flow paths 52 are also arranged side by side in the first direction D1.

[0020] The first flow path 51 and the second flow path 52 may be formed between one end (e.g., the left end) of the support member 40 in the first direction D1 and the cell 20 located closest to one end of the first direction D1 among the multiple cells 20. The first flow path 51 and the second flow path 52 may be formed between the other end (e.g., the right end) of the support member 40 in the first direction D1 and the cell 20 located closest to the other end of the multiple cells 20 in the first direction D1. In other words, the cell 20 may be provided between adjacent first flow paths 51 among the multiple first flow paths 51, or between adjacent second flow paths 52 among the multiple second flow paths 52.

[0021] Between adjacent cells 20, the first flow path 51 and the second flow path 52 are arranged side by side in the third direction D3, here in the vertical direction. In this embodiment, the third direction D3 is an example of a "direction perpendicular to the width direction of the wide surface 21 of the cell 20". Here, the first flow path 51 is arranged above the second flow path 52. However, the first flow path 51 may be arranged below the second flow path 52. Here, as shown in FIG. 3, a partition wall 43 may be provided between the first flow path 51 and the second flow path 52. The partition wall 43 is provided inside the support member 40 and has a plate shape that spreads in the first direction D1 and the second direction D2. The first flow path 51 and the second flow path 52 arranged side by side are partitioned by the partition wall 43.

[0022] In this embodiment, the first flow path 51 and the second flow path 52 may be partially in communication with the support hole 42. For example, in a state in which the cell 20 is accommodated in the support hole 42, the cell 20 may surround a portion of the first flow path 51, or may surround a portion of the second flow path 52. In other words, the cell 20 may form a portion of a member surrounding the first flow path 51, or may form a portion of a member surrounding the second flow path 52.

[0023] As shown in FIG. 3, the U-turn flow path forming member 60 is a member that connects the first flow path 51 and the second flow path 52 formed in the support member 40. The U-turn flow path forming member 60 is disposed on the second side 21b of the wide surface 21 of the plurality of cells 20. Here, the U-turn flow path forming member 60 is disposed on the rear side of the support member 40 in the second direction D2. The U-turn flow path forming member 60 contacts the support member 40 from the rear. The shape of the U-turn flow path forming member 60 is not particularly limited, but is, for example, a rectangular parallelepiped shape. The material forming the U-turn flow path forming member 60 is also not particularly limited, and is, for example, a resin. For example, the U-turn flow path forming member 60 is formed of polypropylene.

[0024] The U-turn flow path forming member 60 has a third flow path 53. Here, an internal space is formed inside the U-turn flow path forming member 60, and the U-turn flow path forming member 60 opens toward the front. The internal space can be the third flow path 53. The third flow path 53 is disposed on the second side 21b of the cell 20, and is a flow path connecting the first flow path 51 and the second flow path 52. The first flow path 51 and the second flow path 52 are in communication with each other via the third flow path 53. The third flow path 53 has a U-shaped or C-shaped cross section when viewed from the first direction D1, for example.

[0025] FIG. 5 is a front view showing the U-turn flow path forming member 60. As shown in FIG. 5, the third flow path 53 has an inlet 53a and an outlet 53b. Here, the inlet 53a and the outlet 53b are formed on the same surface of the U-turn flow path forming member 60, for example, on the front surface of the U-turn flow path forming member 60. The inlet 53a is disposed above the outlet 53b. As shown in FIG. 3, the inlet 53a of the third flow path 53 is connected to the end of the second side 21b of the multiple first flow paths 51 of the support member 40. The outlet 53b of the third flow path 53 is connected to the end of the second side 21b of the multiple second flow paths 52 of the support member 40. A refrigerant passes through the third flow path 53. Here, the refrigerant that has passed through the first flow path 51 as indicated by the arrow A1 passes through the third flow path 53 as indicated by the arrow A3. The refrigerant that has passed through the third flow path 53 passes through the second flow path 52 as indicated by the arrow A2.

[0026] 3, a U-turn partition 62 is formed between the inlet 53a and the outlet 53b. The U-turn partition 62 extends, for example, in the first direction D1 and the second direction D2, and divides the third flow path 53 into a portion on the inlet 53a side and a portion on the outlet 53b side.

[0027] In this embodiment, as shown in FIG. 5, the third flow passage 53 extends in the first direction D1, and the number of the third flow passages 53 formed in the U-turn flow passage forming member 60 is one. Therefore, one third flow passage 53 connects a plurality of first flow passages 51 and a plurality of second flow passages 52. However, the number of the third flow passages 53 may be more than one. In this case, the plurality of third flow passages 53 may be arranged side by side in the first direction D1. One third flow passage 53 may be configured to connect one first flow passage 51 and one second flow passage 52 arranged vertically.

[0028] The cooling device 70 is a device that cools the third flow path 53 formed in the U-turn flow path forming member 60. The cooling device 70 cools the refrigerant flowing through the third flow path 53 and removes heat imparted to the refrigerant. The configuration of the cooling device 70 is not particularly limited. In this embodiment, the cooling device 70 has a Peltier element 72 and a heat dissipation fin 75.

[0029] The Peltier element 72 is a type of plate-shaped semiconductor thermoelectric element that uses the Peltier effect. Here, the Peltier element 72 is disposed in the third flow path 53. As shown in FIG. 5, the Peltier element 72 extends in the first direction D1, and is provided over the entirety of the third flow path 53 in the first direction D1. As shown in FIG. 3, the Peltier element 72 has a cooling surface 73a and a heating surface 73b. The cooling surface 73a is a surface that absorbs heat, and is constituted by a surface of the Peltier element 72 facing the inside of the third flow path 53. The heating surface 73b is a surface that generates heat (or dissipates heat), and is constituted by a surface of the Peltier element 72 facing the outside of the third flow path 53.

[0030] In this embodiment, a current changer 74 that passes a current (e.g., a direct current) through the Peltier element 72 is connected to the Peltier element 72. In the Peltier element 72, the cooling surface 73a is cooled by the current passed from the current changer 74. This cools the third flow path 53, and removes heat from the refrigerant flowing through the third flow path 53.

[0031] The heat dissipation fins 75 are fins for dissipating heat in the third flow path 53 to the outside of the third flow path 53. Here, the heat dissipation fins 75 are provided on the U-turn flow path forming member 60 so that at least a part of the heat dissipation fins 75 is disposed in the third flow path 53. As shown in FIG. 5, the number of the heat dissipation fins 75 is plural, and the plural heat dissipation fins 75 are arranged side by side in the first direction D1. The number of the heat dissipation fins 75 is not limited, and is a predetermined number that is appropriately set according to the size and number of the cells 20. As shown in FIG. 3, the heat dissipation fins 75 are plate-shaped and extend in the second direction D2 and the third direction D3. The material for forming the heat dissipation fins 75 is not particularly limited, and is preferably a material that easily dissipates heat to the outside. Here, the heat dissipation fins 75 are formed of metal. More specifically, the heat dissipation fins 75 are formed of copper or aluminum. In this embodiment, the heat dissipation fins 75 are cooled by the Peltier element 72. As a result, the cooled heat dissipation fins 75 can cool the third flow path 53.

[0032] The heat dissipating fin 75 is provided so as to communicate with the inside and outside of the third flow path 53. Here, the heat dissipating fin 75 penetrates a part (here, the rear wall) of the U-turn flow path forming member 60 forming a part of the third flow path 53. In this embodiment, the heat dissipating fin 75 has an inner part 76a and an outer part 76b. The inner part 76a is disposed inside the third flow path 53. The outer part 76b is disposed outside the third flow path 53, in other words, outside the U-turn flow path forming member 60. The outer part 76b is provided on the opposite side of the support member 40 with respect to the U-turn flow path forming member 60 (here, the rear side of the U-turn flow path forming member 60). The outer part 76b is continuous with the inner part 76a.

[0033] As shown in FIG. 3, the refrigerant supplying device 80 is configured to supply the refrigerant to the first flow path 51 of the support member 40. Here, the refrigerant supplying device 80 supplies the refrigerant from the first side 21a (here, the front side) of the first flow path 51. The refrigerant supplying device 80 is disposed on the opposite side of the U-turn flow path forming member 60 with respect to the support member 40 (here, the front side of the support member 40). The number of the refrigerant supplying devices 80 is not particularly limited. In this embodiment, as shown in FIG. 1, one refrigerant supplying device 80 is provided for one first flow path 51. However, one refrigerant supplying device 80 may be provided for a plurality of first flow paths 51. When there are a plurality of refrigerant supplying devices 80, the plurality of refrigerant supplying devices 80 are arranged side by side in the first direction D1 on the front side of the support member 40.

[0034] The type of refrigerant supplied by the refrigerant supply device 80 is not particularly limited. The refrigerant is a fluid. Here, the refrigerant is a gas, for example, air. The refrigerant supply device 80 supplies air as the refrigerant to the first flow path 51. The configuration of the refrigerant supply device 80 is not particularly limited. Here, the refrigerant supply device 80 has a function of blowing air to the first flow path 51. As shown in FIG. 3, the refrigerant supply device 80 has a fan 81. When the fan 81 is driven (or rotated), air as the refrigerant is supplied from the first side 21a to the first flow path 51. Although not shown, the refrigerant supply device 80 may have a cooling mechanism that cools the refrigerant supplied to the first flow path 51.

[0035] In this embodiment, the coolant supply device 80 is supported by a support plate 85 arranged on the front side of the support member 40. The support plate 85 is a plate-like member extending in the first direction D1 and the second direction D2. The coolant supply device 80 is placed on the support plate 85. The support plate 85 is supported by legs 86 and 87 extending vertically. The leg 86 is connected to the left end of the support plate 85. The leg 87 is connected to the right end of the support plate 85.

[0036] In this embodiment, the cells 20 may be heated by charging and discharging the cells 20 supported by the support member 40. At this time, the entire cells 20 may be heated. As shown in FIG. 3, in the battery pack 10 according to this embodiment, the coolant supply device 80 is driven, so that the coolant supply device 80 supplies the coolant from the first side 21a to the first flow path 51. The coolant supplied to the first flow path 51 is the air around the battery pack 10, and is not heated. The coolant supplied to the first flow path 51 passes through the first flow path 51 from the first side 21a to the second side 21b as indicated by the arrow A1. At this time, the part of the cell 20 located around the first flow path 51 (typically the upper part of the cell 20) is cooled by the coolant flowing through the first flow path 51. On the other hand, the heat of the cell 20 is imparted to the coolant, so that the coolant is heated and becomes warm. The warmed coolant flows from the first flow path 51 to the third flow path 53 formed in the U-turn flow path forming member 60.

[0037] As described above, the third flow path 53 is provided with the cooling device 70 (here, the Peltier element 72 and the heat dissipation fins 75). When a current flows from the current transformer 74 to the Peltier element 72, the cooling surface 73a of the Peltier element 72 is cooled. When the Peltier element 72 is cooled, the heat dissipation fins 75 are cooled. Therefore, as shown by the arrow A3 in FIG. 3, the refrigerant flowing through the third flow path 53 is actively cooled by the Peltier element 72 and the heat dissipation fins 75, and heat is removed. As a result, the refrigerant that has flowed through the third flow path 53 and been cooled is supplied from the second side 21b to the second flow path 52. The refrigerant supplied to the second flow path 52 passes through the second flow path 52 from the second side 21b toward the first side 21a, as shown by the arrow A2. At this time, a portion of the cell 20 located around the second flow path 52 (typically a lower portion of the cell 20) is cooled by the refrigerant flowing through the second flow path 52. On the other hand, the refrigerant flowing through the second flow passage 52 is heated and becomes warm as the heat of the cell 20 is imparted to the refrigerant. The warmed refrigerant is then discharged to the outside from the first side 21a of the second flow passage 52. In this manner, the entire cell 20 can be uniformly cooled.

[0038] As described above, in this embodiment, as shown in FIG. 1, the battery pack 10 includes a plurality of cells 20 each having a pair of wide surfaces 21 (see FIG. 2) facing each other, a support member 40 supporting the plurality of cells 20, a U-turn flow path forming member 60, and a coolant supply device 80. As shown in FIG. 2, the support member 40 is configured to arrange the plurality of cells 20 with the wide surfaces 21 facing each other with a gap therebetween. As shown in FIG. 3 and FIG. 4, the support member 40 has a first flow path 51 between adjacent cells 20 among the plurality of cells 20, which runs from the first side 21a to the second side 21b in the width direction (here, the second direction D2) of the wide surface 21, and a second flow path 52 independent of the first flow path 51 and running from the second side 21b to the first side 21a. As shown in FIG. 3, the U-turn flow path forming member 60 is arranged on the second side 21b of the wide surfaces 21 of the plurality of cells 20, and has a third flow path 53 connecting the first flow path 51 and the second flow path 52. The refrigerant supply device 80 is configured to supply the refrigerant from the first side 21a of the first flow path 51. In this manner, the refrigerant supplied from the refrigerant supply device 80 passes through the first flow path 51 as indicated by the arrow A1, thereby cooling a portion of the cell 20 located around the first flow path 51 (here, the upper portion of the cell 20). In addition, the refrigerant that passes through the first flow path 51 and reaches the third flow path 53 passes through the second flow path 52 as indicated by the arrow A2, thereby cooling a portion of the cell 20 located around the second flow path 52 (here, the lower portion of the cell 20). Thus, the entire cell 20 can be uniformly cooled by the refrigerant passing through the first flow path 51 and the second flow path 52.

[0039] In this embodiment, as shown in FIG. 3, the battery pack 10 includes a cooling device 70 that cools the third flow path 53. For example, when the refrigerant passes through the first flow path 51, the refrigerant may absorb heat from the cells 20, and thus heat may be imparted to the refrigerant, causing it to be warmed. Therefore, the refrigerant that reaches the third flow path 53 from the first flow path 51 may be warm. However, in this embodiment, the third flow path 53 is cooled by the cooling device 70, so that the refrigerant passing through the third flow path 53 can be cooled. Therefore, the cooled refrigerant can pass through the second flow path 52, and therefore the cells 20 can be further cooled.

[0040] In this embodiment, the cooling device 70 has a Peltier element 72. The Peltier element 72 can actively absorb heat from the refrigerant passing through the third flow path 53 of the U-turn flow path forming member 60. Therefore, the refrigerant from which heat has been actively absorbed can be supplied to the second flow path 52.

[0041] In this embodiment, the cooling device 70 has at least a heat dissipation fin 75 provided in the third flow path 53. The Peltier element 72 cools the heat dissipation fin 75. This allows the heat dissipation fin 75 to be cooled by the Peltier element 72. Therefore, the cooled heat dissipation fin 75 can easily absorb the heat of the refrigerant in the third flow path 53. Therefore, a more cooled refrigerant can be supplied to the second flow path 52.

[0042] In this embodiment, the heat dissipation fins 75 are provided so as to communicate with the inside and outside of the third flow path 53. This allows the heat absorbed by the heat dissipation fins 75 in the third flow path 53 to be dissipated to the outside of the third flow path 53. This makes it difficult for heat to remain in the third flow path 53, making it easier to cool the refrigerant passing through the third flow path 53.

[0043] In this embodiment, the first flow paths 51 and the second flow paths 52 are arranged side by side in a direction (here, the third direction D3) perpendicular to the width direction (here, the second direction D2) of the wide faces 21 of the multiple cells 20. This allows the cells 20 to be cooled to a uniform temperature in the third direction D3 by the refrigerant passing through the first flow paths 51 and the second flow paths 52.

[0044] In this embodiment, as shown in FIG. 4, there is one first flow path 51 and one second flow path 52 between adjacent cells 20. However, there may be a plurality of first flow paths 51 and a plurality of second flow paths 52 between adjacent cells 20. FIG. 6 is a front view showing a support member 40 of a battery pack 10A according to another embodiment. FIG. 7 is a cross-sectional view showing a battery pack 10A according to another embodiment, and is a view equivalent to FIG. 3. For example, as shown in FIG. 6, one first flow path 51 and two second flow paths 52A and 52B may be provided between adjacent cells 20 in the first direction D1. In this case, the first flow path 51 is sandwiched between, for example, two second flow paths 52A and 52B. As shown in FIG. 7, the second flow path 52A is formed in the support member 40 so as to be disposed above the first flow path 51. The second flow path 52B is formed in the support member 40 so as to be disposed below the first flow path 51. Here, a partition wall 43A is provided between the first flow path 51 and the second flow path 52A. A partition wall 43B is provided between the first flow path 51 and the second flow path 52B. The partition wall 43A separates the first flow path 51 from the second flow path 52A. The partition wall 43B separates the first flow path 51 from the second flow path 52B.

[0045] In this case, the third flow path 53 formed in the U-turn flow path forming member 60 has one inlet 53a and two outlets 53b1, 53b2. The inlet 53a is sandwiched between, for example, the two outlets 53b1, 53b2. The outlet 53b1 is disposed above the inlet 53a and is connected to the end of the second side 21b of the second flow path 52A. The outlet 53b2 is disposed below the inlet 53a and is connected to the end of the second side 21b of the second flow path 52B. In this case, the third flow path 53 is configured such that the inlet 53a and the two outlets 53b1, 53b2 communicate with each other. Here, a U-turn partition wall 62A is provided between the inlet 53a and the outlet 53b1. A U-turn partition wall 62B is provided between the inlet 53a and the outlet 53b2. In this manner, the U-turn partitions 62A and 62B divide the third flow path 53 into an inlet 53a portion, an outlet 53b1 side portion, and an outlet 53b2 side portion.

[0046] In the example of FIG. 6 and FIG. 7, the refrigerant supplied to the first flow path 51 passes through the first flow path 51 from the first side 21a to the second side 21b as indicated by the arrow A11. At this time, a portion of the cell 20 located around the first flow path 51 (typically the central portion of the cell 20 from above to below) is cooled by the refrigerant flowing through the first flow path 51. Then, in the third flow path 53, the refrigerant is cooled by the cooling device 70. The cooled refrigerant is supplied to either the second flow path 52A or 52B as indicated by the arrows A13a and A13b. Here, the refrigerant supplied to the second flow path 52A passes through the second flow path 52A from the second side 21b to the first side 21a as indicated by the arrow A12a. At this time, a portion of the cell 20 located around the second flow path 52A (typically the upper portion of the cell 20) is cooled by the refrigerant flowing through the second flow path 52A. On the other hand, the refrigerant supplied to the second flow path 52B passes through the second flow path 52B from the second side 21b toward the first side 21a as indicated by the arrow A12b. At this time, a portion of the cell 20 located around the second flow path 52B (typically a lower portion of the cell 20) is cooled by the refrigerant flowing through the second flow path 52B. In this way, even in the example shown in FIG. 6 and FIG. 7, the entire cell 20 can be uniformly cooled.

[0047] In this embodiment, the first flow path 51 and the second flow path 52 extend in the second direction D2, that is, the front-rear direction. However, the first flow path 51 and the second flow path 52 may extend in the up-down direction. That is, for example, in the example of FIG. 6 and FIG. 7, the battery pack 10 may be rotated 90 degrees (for example, the front part of the battery pack 10 is rotated 90 degrees upward) around the first direction D1 as an axis. For example, in the example of FIG. 6 and FIG. 7, the second direction D2 may be changed from the front-rear direction to the up-down direction, and the third direction D3 may be changed from the up-down direction to the front-rear direction. In this case, for example, the coolant supply device 80 may be disposed above the support member 40, and the U-turn flow path forming member 60 may be disposed below the support member 40. Even in this case, the same effect as the example of FIG. 6 and FIG. 7 can be obtained.

[0048] The invention disclosed herein has been described in various ways. Unless otherwise specified, the embodiments described herein do not limit the present invention. Furthermore, the embodiments of the invention disclosed herein can be modified in various ways, and each component or each process described herein can be omitted or combined as appropriate, unless a particular problem occurs.

[0049] As described above, this specification includes the disclosures set forth in the following sections. Section 1: A plurality of cells each having a pair of opposing wide surfaces; A support member for supporting the plurality of cells; A U-turn flow path forming member; A refrigerant supply device; Equipped with The support member is configured to arrange the plurality of cells with the broad surfaces facing each other with a gap therebetween; The support member is A first flow path extending from a first side to a second side in a width direction of the wide surface between adjacent cells among the plurality of cells; A second flow path that is independent of the first flow path and extends from the second side to the first side; having the U-turn flow path forming member is disposed on the second side of the wide surface of the plurality of cells, and has a third flow path connecting the first flow path and the second flow path, The coolant supply device is configured to supply a coolant from the first side of the first flow path.

[0050] Section 2: Item 1. The battery pack according to item 1, further comprising a cooling device for cooling the third flow path.

[0051] Section 3: Item 3. The battery pack according to item 2, wherein the cooling device has a Peltier element.

[0052] Section 4: The cooling device has a heat dissipation fin provided at least in the third flow path, Item 4. The battery pack according to item 3, wherein the Peltier element cools the heat dissipation fins.

[0053] Section 5: 5. The battery pack according to item 4, wherein the heat dissipation fin is provided so as to communicate with the inside and outside of the third flow path.

[0054] Item 6: 6. The battery pack according to any one of items 1 to 5, wherein the first flow path and the second flow path are arranged side by side in a direction perpendicular to a width direction of the wide faces of the plurality of cells. [Explanation of symbols]

[0055] 10 Battery pack 20 cells 21 Wide surface 21a 1st side 21b 2nd side 40 Support member 51 First Channel 52 Second Flow Path 53 Third Stream 60 U-turn flow path forming member 70 Cooling device 72 Peltier element 75 Heat dissipation fin 80 Refrigerant supply device D1 1st direction D2 Second direction (width direction of wide surface) D3 Third direction

Claims

1. A plurality of cells each having a pair of opposing wide surfaces; A support member for supporting the plurality of cells; A U-turn flow path forming member; A refrigerant supply device; Equipped with The support member is configured to arrange the plurality of cells with the wide surfaces facing each other with a gap therebetween; The support member is A first flow path extending from a first side to a second side in a width direction of the wide surface between adjacent cells among the plurality of cells; A second flow path that is independent of the first flow path and extends from the second side to the first side; having The U-turn flow path forming member is disposed on the second side of the wide surface of the plurality of cells, and has a third flow path connecting the first flow path and the second flow path, the coolant supply device is configured to supply a coolant from the first side of the first flow path.

2. The battery pack according to claim 1 , further comprising a cooling device that cools the third flow path.

3. The battery pack according to claim 2 , wherein the cooling device includes a Peltier element.

4. The cooling device has a heat dissipation fin provided at least in the third flow path, The battery pack according to claim 3 , wherein the Peltier element cools the heat dissipation fins.

5. The battery pack according to claim 4 , wherein the heat dissipation fin is provided so as to communicate with an inside and an outside of the third flow path.

6. The battery pack according to claim 1 , wherein the first flow path and the second flow path are arranged side by side in a direction perpendicular to a width direction of the wide faces of the plurality of cells.

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