Battery pack and vehicle

Abstract

To provide an electrode body manufacturing method capable of suppressing the enlargement of a heat insulation member.SOLUTION: A battery pack 100 includes a plurality of battery cells 10 stacked on each other in an X direction (first direction), and a plurality of separator parts 40 provided between the adjacent battery cells 10. Each of the battery cells 10 includes a curved part 12 (first end part) that exists on one end of the battery cell 10 in a Y direction (second direction), a curved part 13 (second end part) that exists on the other end of the battery cell 10 in the Y direction, and a flat part 11 (intermediate part) provided between the curved part 12 and the curved part 13. Each of the separator parts 40 includes a heat insulation member 41 provided between the flat parts 11 adjacent to each other in the X direction, and a first shielding plate 42 provided separately from the heat insulation member 41 between the curved parts 12 adjacent to each other in the X direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a battery pack and a vehicle. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2020-187859 (Patent Document 1) discloses a battery pack in which a plurality of secondary batteries are arranged side by side in a predetermined direction. The battery pack includes a heat insulating sheet arranged between the secondary batteries adjacent to each other in the predetermined direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-187859 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 does not take into consideration the prevention of the heat insulating sheet (heat insulating member) from becoming large. It is effective to make the heat insulating member small in order to reduce the weight and cost of the battery pack. Therefore, it is desirable to prevent the heat insulating sheet from becoming large.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a battery pack and a vehicle that are capable of preventing an increase in size of a heat insulating member. [Means for solving the problem]

[0006] A battery pack according to a first aspect of the present disclosure includes a plurality of battery cells stacked together in a first direction and a plurality of separator portions provided between adjacent battery cells. Each of the plurality of battery cells includes a first end portion located at one end of the battery cell in a second direction perpendicular to the first direction, a second end portion located at the other end of the battery cell in the second direction, and an intermediate portion provided between the first end portion and the second end portion. Each of the plurality of separator portions includes a heat insulating member provided between adjacent intermediate portions in the first direction, and a first shielding plate provided separately from the heat insulating member between adjacent first end portions in the first direction.

[0007] In the battery pack according to the first aspect of the present disclosure, as described above, each of the multiple separator portions includes a heat insulating member provided between adjacent intermediate portions in the first direction, and a first shielding plate provided separately from the heat insulating member between adjacent first end portions in the first direction. This makes it possible to prevent the heat insulating member from becoming larger (the amount of heat insulating member from increasing) compared to a case in which a heat insulating member is also provided between adjacent first end portions in the first direction.

[0008] In the battery pack according to the first aspect, the intermediate portion preferably includes a flat portion having a constant width in the first direction. The first end portion includes a narrow portion having a smaller width in the first direction than the flat portion. The first shielding plate is provided between adjacent narrow portions in the first direction. With this configuration, it is possible to further prevent the insulating member from becoming larger (the amount of insulating member from increasing) compared to a case where the insulating member is laid out between the narrow portions (the space between the narrow portions is filled with the insulating member).

[0009] The battery pack according to the first aspect preferably further includes a case that houses the plurality of battery cells. The first shielding plate is in contact with the case. With this configuration, when the temperature of the first shielding plate increases due to radiant heat from the battery cells, the heat of the first shielding plate can be easily transferred (dissipated) to the case. Note that emissivity represents the ease of thermal radiation (heat transfer) from an object.

[0010] In the battery pack according to the first aspect, the first shielding plate preferably has a first surface facing a battery cell that is located at the center in the first direction among the plurality of battery cells, and a second surface opposite to the first surface. The emissivity of the second surface is greater than the emissivity of the first surface. Here, the number of battery cells located on the side of the battery cell located at the center in the first direction as viewed from each of the plurality of battery cells (battery cells other than the central battery cell) is greater than the number of battery cells located on the opposite side. Specifically, when five battery cells are lined up in the left-right direction, for example, as viewed from the second battery cell from the left, three battery cells are located on the center side (right side) while only one battery cell is located on the opposite side (left side). Therefore, as viewed from each of the plurality of battery cells, the battery cell located at the center in the first direction has a larger heat capacity (heat capacity of the battery cell) than the opposite side. Therefore, by making the emissivity of the second surface greater than the emissivity of the first surface, heat can be more efficiently transferred to the center side where the heat capacity is larger.

[0011] In the battery pack according to the first aspect, the first shielding plate and the first end portion adjacent to each other in the first direction are preferably spaced apart from each other. With this configuration, it is possible to suppress transfer of heat from the first shielding plate to the battery cell (the first end portion).

[0012] In the battery pack according to the first aspect, the heat insulating member and the first shielding plate are preferably in contact with each other in each of the plurality of separator portions. With this configuration, heat transferred from the battery cell to the heat insulating member can be transferred (dissipated) to the first shielding plate.

[0013] In the battery pack according to the first aspect, each of the separator portions preferably includes a second shielding plate provided separately from the heat insulating member between the second ends adjacent to each other in the first direction. With this configuration, it is possible to prevent the heat insulating member from becoming larger (the amount of the heat insulating member from increasing) compared to a case where a heat insulating member is also provided between the second ends adjacent to each other in the first direction.

[0014] In the battery pack according to the first aspect, the battery pack is preferably mounted on a rover traveling on the lunar surface. Since there is no air on the lunar surface, the amount of heat dissipated from the battery cells is smaller than on the earth. Since the amount of heat dissipated from the battery cells is smaller, heat transfer from one battery cell to an adjacent battery cell occurs relatively easily. In other words, a heat dissipation path is easily formed between adjacent battery cells. Therefore, suppressing the transfer of heat between the first ends by the first shielding plate is particularly effective in suppressing a rise in temperature of the battery cells when the battery pack is mounted on a rover traveling on the lunar surface.

[0015] A vehicle according to a second aspect of the present disclosure is equipped with the battery pack according to the first aspect, thereby providing a vehicle that can prevent the heat insulating member from becoming larger (the amount of heat insulating member from increasing) compared to a case in which a heat insulating member is provided between the first ends adjacent to each other in the first direction. Effect of the Invention

[0016] According to the present disclosure, it is possible to prevent the size of the insulating member from increasing. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 illustrates a lunar rover equipped with a battery pack according to one embodiment. [Diagram 2] 1 is a cross-sectional view showing a configuration of a battery pack according to one embodiment. [Diagram 3] FIG. 2 is a partially enlarged view of the vicinity of a curved portion of a battery cell according to one embodiment. [Figure 4] FIG. 4 is a partial enlarged view of the vicinity of a curved portion of a central battery cell according to one embodiment. [Diagram 5] FIG. 11 is a cross-sectional view showing a configuration of a first shielding plate according to a first modified example of an embodiment. [Figure 6] FIG. 11 is a cross-sectional view showing a configuration of a first shielding plate according to a second modified example of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and the description thereof will not be repeated.

[0019] 1 is a diagram showing the configuration of a lunar rover 1 according to this embodiment. The lunar rover 1 travels on a lunar surface 2. The lunar rover 1 is a vehicle for exploring the lunar surface 2. The lunar rover 1 is an example of the "rover" and "vehicle" of the present disclosure.

[0020] The lunar rover 1 is equipped with an internal battery pack 100. The lunar rover 1 runs on the power of the battery pack 100.

[0021] As shown in Fig. 2, the battery pack 100 includes a plurality of battery cells 10 stacked on top of one another. Fig. 2 illustrates an example in which five battery cells 10 are arranged side by side along the X direction. The plurality of battery cells 10 have the same configuration. The X direction is an example of a "first direction" in the present disclosure.

[0022] Each of the multiple battery cells 10 includes a flat portion 11, a curved portion 12, and a curved portion 13. The curved portion 12 is located at the end of the battery cell 10 on the Y1 side. The curved portion 13 is located at the end of the battery cell 10 on the Y2 side. The flat portion 11 is provided between the curved portion 12 and the curved portion 13. The curved portion 12 and the curved portion 13 have the same shape. The Y direction is a direction perpendicular to the X direction, and is an example of the "second direction" of the present disclosure. The flat portion 11 is an example of the "middle portion" of the present disclosure. The curved portion 12 and the curved portion 13 are examples of the "first end" and the "second end" of the present disclosure, respectively. The curved portion 12 is an example of the "narrow width portion" of the present disclosure.

[0023] The flat portion 11 has a constant width W1 in the X direction. The width W2 of the curved portion 12 in the X direction is smaller than the width W1 of the flat portion 11. The width W3 of the curved portion 13 in the X direction is smaller than the width W1 of the flat portion 11.

[0024] Each of curved portions 12 and 13 has a semicircular shape in a cross-sectional view along the XY plane (cross-sectional view shown in FIG. 2). This makes it possible to increase the mechanical strength of battery cell 10 and reduce the weight of battery cell 10 compared to a case in which battery cell 10 has a rectangular shape. The Y direction is a direction perpendicular to the X direction.

[0025] The battery pack 100 also includes a case 20 that houses the multiple battery cells 10. The case 20 includes an upper case 21 provided on the Y1 side of the multiple battery cells 10. The case 20 also includes a lower case 22 provided on the Y2 side of the multiple battery cells 10. The upper case 21 and the lower case 22 are each provided to extend along the X direction. Each of the multiple battery cells 10 is in contact with the lower case 22. The upper case 21 and the lower case 22 are each formed in a plate shape. The case 20 (21, 22) is formed of aluminum, for example.

[0026] Each of the multiple battery cells 10 and the lower case 22 are in contact with each other via a thermal conductor 30. The thermal conductor 30 conducts heat between the battery cells 10 and the lower case 22. The thermal conductor 30 is made of, for example, a resin that has a relatively low thermal resistance (relatively high thermal conductivity) and a relatively high elasticity (viscosity). Since the elasticity (viscosity) of the thermal conductor 30 is relatively high, even if there is variation in size, arrangement position, etc. among the multiple battery cells 10, the thermal conductor 30 can absorb the variation.

[0027] The battery pack 100 also includes a plurality of separator members 40 provided between adjacent battery cells 10. Each of the plurality of separator members 40 includes a heat insulating member 41, a first shielding plate 42, and a second shielding plate 43. The first shielding plate 42 and the second shielding plate 43 are each provided separately from the heat insulating member 41. The first shielding plate 42 and the second shielding plate 43 have the same configuration.

[0028] The heat insulating member 41 is provided between the flat portions 11 adjacent to each other in the X direction. Specifically, the heat insulating member 41 is sandwiched between the flat portions 11 adjacent to each other in the X direction. The heat insulating member 41 is made of, for example, a foamed plastic heat insulating material. The heat insulating member 41 may be made of a fiber heat insulating material.

[0029] The first shielding plate 42 is provided between the curved portions 12 adjacent to each other in the X direction. The first shielding plate 42 is provided so as to separate (partition) the curved portions 12 adjacent to each other in the X direction.

[0030] The second shielding plate 43 is provided between the curved portions 13 adjacent to each other in the X direction. The second shielding plate 43 is provided so as to separate (partition) the curved portions 13 adjacent to each other in the X direction.

[0031] The first shielding plate 42 is in contact with the case 20 (upper case 21). Specifically, the first shielding plate 42 is provided so as to extend (protrude) from the upper case 21 toward the heat insulating member 41 side (Y2 side). The first shielding plate 42 is fixed to the upper case 21 by welding, screw fastening, or the like. That is, the first shielding plate 42 and the upper case 21 are separate members. The first shielding plate 42 and the upper case 21 may be integrally formed as a single member. The first shielding plate 42 is made of aluminum, for example. The thermal resistance of the first shielding plate 42 is smaller than the thermal resistance of the heat insulating member 41.

[0032] The second shielding plate 43 is provided so as to extend (protrude) from the lower case 22 toward the heat insulating member 41 side (Y1 side). The second shielding plate 43 is fixed to the lower case 22 by welding, screw fastening, or the like. That is, the second shielding plate 43 and the lower case 22 are separate members. Note that the second shielding plate 43 and the lower case 22 may be integrally formed as a single member.

[0033] In this embodiment, the first shielding plate 42 and the curved portion 12 adjacent to each other in the X direction are spaced apart from each other. Specifically, the thickness t1 of the first shielding plate 42 in the X direction is smaller than the thickness t2 of the heat insulating member 41 in the X direction. The thickness t1 of the first shielding plate 42 and the thickness t2 of the heat insulating member 41 are each constant. In addition, the distance D between the curved portions 12 adjacent to each other gradually increases toward the Y1 side. The thickness t1 of the first shielding plate 42 is smaller than the minimum value of the distance D1.

[0034] Similarly to the first shielding plate 42 and the curved portion 12, the second shielding plate 43 and the curved portion 13 adjacent to each other in the X direction are spaced apart from each other. Note that the detailed description is the same as that of the first shielding plate 42 and the curved portion 12, and therefore will not be repeated.

[0035] In this embodiment, the heat insulating member 41 and the first shielding plate 42 are in contact with each other in each of the multiple separator portions 40. Specifically, an end face 41a of the heat insulating member 41 on the first shielding plate 42 side (Y1 side) and an end face 42a of the first shielding plate 42 on the heat insulating member 41 side (Y2 side) are in contact with each other (close contact).

[0036] In addition, the heat insulating member 41 and the second shielding plate 43 are in contact with each other in each of the multiple separator portions 40. Note that the detailed description is similar to the description of the first shielding plate 42 and the heat insulating member 41 described above, and therefore will not be repeated.

[0037] Each of the multiple first shielding plates 42 has a first surface 42b that faces the battery cell 10 that is located at the center in the X direction among the multiple battery cells 10. Each of the multiple first shielding plates 42 has a second surface 42c on the opposite side (back side) of the first surface 42b. Specifically, in the example shown in FIG. 2, in the two first shielding plates 42 on the X1 side, the first surface 42b faces the X2 side, and the second surface 42c faces the X1 side. On the other hand, in the two first shielding plates 42 on the X2 side, the first surface 42b faces the X1 side, and the second surface 42c faces the X2 side.

[0038] Here, in this embodiment, the emissivity of the second surface 42c is greater than the emissivity of the first surface 42b. When viewed from each of the multiple battery cells 10, the side of the battery cell 10 located at the center in the X direction has a greater heat capacity (heat capacity of the battery cell 10) than the opposite side. Therefore, by making the emissivity of the second surface 42c greater than the emissivity of the first surface 42b, heat can be more efficiently transferred to the center side where the heat capacity is greater.

[0039] 3, each of the first surface 42b and the second surface 42c has projections and recesses. The first shielding plate 42 is formed such that the surface roughness of the second surface 42c is greater than the surface roughness of the first surface 42b. This makes the emissivity of the second surface 42c greater than the emissivity of the first surface 42b. The second shielding plate 43 is configured similarly to the first shielding plate 42, and therefore detailed description thereof will not be repeated.

[0040] Furthermore, among the multiple first shielding plates 42, the first shielding plates 42 that are disposed closer to the central battery cell 10 have a lower emissivity. In other words, among the multiple first shielding plates 42, the first shielding plates 42 that are disposed closer to the ends in the X direction have a higher emissivity. This makes it possible to more efficiently transfer heat to the central side, which has a larger heat capacity.

[0041] In Fig. 3, the first shielding plate 42 on the X2 side is disposed closer to the central battery cell 10 than the first shielding plate 42 on the X1 side. In this case, the first surface 42b of the first shielding plate 42 on the X1 side has a larger surface roughness and a larger emissivity than the first surface 42b of the second shielding plate 43 on the X2 side. In addition, the second surface 42c of the first shielding plate 42 on the X1 side has a larger surface roughness and a larger emissivity than the second surface 42c of the second shielding plate 43 on the X2 side. The same applies to the multiple second shielding plates 43.

[0042] As shown in FIG. 4, the two first shielding plates 42 arranged to sandwich the central battery cell 10 (curved portion 12) are provided with their orientations reversed from each other and have the same configuration. Specifically, the first surface 42b of the first shielding plate 42 on the X1 side of FIG. 4 and the second surface 42c of the first shielding plate 42 on the X2 side have the same surface roughness (emissivity). The second surface 42c of the first shielding plate 42 on the X1 side and the first surface 42b of the first shielding plate 42 on the X2 side have the same surface roughness (emissivity). The same is true for the two second shielding plates 43 that sandwich the central battery cell 10. The first shielding plate 42 (second shielding plate 43) closest to the X1 side and the first shielding plate 42 (second shielding plate 43) closest to the X2 side may be provided with their orientations reversed from each other and have the same configuration.

[0043] 2, the battery pack 100 includes an end plate 50 provided on the X1 side of the battery cell 10 closest to the X1 side. The end plate 50 is provided so as to cover the entire battery cell 10 closest to the X1 side from the X1 side. The end plate 50 and the battery cell 10 closest to the X1 side (flat portion 11) are in contact (close contact) with each other. The end plate 50 is made of aluminum, for example.

[0044] The battery pack 100 also includes an end plate 51 arranged on the X2 side of the battery cell 10 closest to the X2 side. The end plate 51 is provided so as to cover the entire battery cell 10 closest to the X2 side from the X2 side. The end plate 51 and the battery cell 10 closest to the X2 side (flat portion 11) are in contact (close contact) with each other. The end plate 51 is made of aluminum, for example.

[0045] Each of the end plate 50 and the end plate 51 is fixed to the lower case 22. A connection portion 50a connected to the lower case 22 is provided at an end of the end plate 50 on the lower case 22 side (Y2 side). A connection portion 51a connected to the lower case 22 is provided at an end of the end plate 51 on the lower case 22 side (Y2 side). The end plate 50 (51) is fixed to the lower case 22 by fastening or welding the connection portion 50a (51a) to the lower case 22.

[0046] As described above, in this embodiment, each of the multiple separator members 40 includes a heat insulating member 41 provided between the flat portions 11 adjacent to each other in the X direction, and a first shielding plate 42 provided separately from the heat insulating member 41 between the curved portions 12 adjacent to each other in the X direction. By providing the first shielding plate 42 between the curved portions 12, it is not necessary to use a heat insulating member to block radiant heat between the curved portions 12. As a result, it is possible to prevent the heat insulating member from becoming large.

[0047] In the above embodiment, the first shielding plate 42 and the curved portion 12 adjacent to each other are spaced apart from each other, but the present disclosure is not limited to this. The first shielding plate and the curved portion 12 may be in contact with each other.

[0048] 5, the first shielding plate 142 is in contact with each of the curved portion 12 on the X1 side and the curved portion 12 on the X2 side. The first shielding plate 142 includes a portion 142a extending from the upper case 21 to the Y2 side, and a portion 142b sandwiched between the portion 142a and the heat insulating member 41 in the Y direction.

[0049] The thickness t11 of the portion 142a in the X direction is constant. That is, the portion 142a has a flat shape. The thickness t12 of the portion 142b in the X direction gradually decreases toward the heat insulating member 41 side (Y2 side). The portion 142b has a tapered shape tapering toward the heat insulating member 41 side (Y2 side). Specifically, the portion 142b has a pair of inclined surfaces 142c that contact each of the curved portion 12 on the X1 side and the curved portion 12 on the X2 side. Each of the pair of inclined surfaces 142c is formed in a flat surface shape. Note that each of the pair of inclined surfaces 142c may be formed in a curved surface shape. Also, the end surface 142d on the Y2 side of the portion 142b and the end surface 41a on the Y1 side of the heat insulating member 41 are in contact (close contact) with each other.

[0050] With this configuration, heat from the battery cells 10 can be effectively transferred (dissipated) to the upper case 21 via the first shielding plate 142.

[0051] 6 is a modified example of the first shielding plate 142 in FIG. 5. Of the two adjacent curved portions 12, the first shielding plate 242 is in contact only with the curved portion 12 of the battery cell 10 on the X1 side (the battery cell 10 opposite the central battery cell 10). The first shielding plate 242 has a flat portion 242a and a tapered portion 242b. The portion 242b has an inclined surface 242c that contacts the curved portion 12 on the X1 side. This makes it possible to easily transfer heat from the battery cell 10 opposite the central battery cell 10 to the central battery cell 10, which has a larger heat capacity.

[0052] The configurations of the first shielding plate 142 and the first shielding plate 242 shown in FIG. 5 and FIG. 6 may be applied to the second shielding plate.

[0053] In addition, in the above embodiment, an example has been described in which the battery cell 10 includes the curved portion 12 and the curved portion 13, but the present disclosure is not limited to this. For example, the battery cell may be composed of only a flat portion.

[0054] In the above embodiment, the first shielding plate 42 and the second shielding plate 43 are in contact with the heat insulating member 41, but the present disclosure is not limited to this. At least one of the first shielding plate 42 and the second shielding plate 43 does not have to be in contact with the heat insulating member 41.

[0055] In the above embodiment, the emissivity is made different between the first surface 42b and the second surface 42c of the first shielding plate 42 by making the surface roughness due to unevenness different from each other, but the present disclosure is not limited to this. For example, the emissivity may be made different between the first surface 42b and the second surface 42c by gloss, oxidation state, dirt state, etc. Also, a first shielding plate having a first surface and a second surface with different emissivity may be formed by bonding plate members with different emissivities.

[0056] In addition, in the above embodiment, an example has been described in which the battery pack 100 is mounted on the lunar rover 1, but the present disclosure is not limited to this. For example, the battery pack 100 may be mounted on a ground vehicle.

[0057] The configurations described in the above embodiment and the various modified examples may be implemented in any combination.

[0058] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0059] 1 lunar rover (explorer) (vehicle), 2 lunar surface, 10 battery cell, 11 flat portion (middle portion), 12 curved portion (first end) (narrow width portion), 13 curved portion (second end), 20 case, 40 separator portion, 41 heat insulating member, 42 first shielding plate, 42b first surface, 42c second surface, 43 second shielding plate, 100 battery pack, X direction (first direction), Y direction (second direction).

Claims

1. A plurality of battery cells stacked on top of each other in a first direction; a plurality of separator portions provided between adjacent battery cells; Each of the plurality of battery cells is a first end portion located at one end of the battery cell in a second direction perpendicular to the first direction; a second end portion located at the other end of the battery cell in the second direction; an intermediate portion provided between the first end and the second end, Each of the plurality of separator portions is A heat insulating member provided between the intermediate portions adjacent to each other in the first direction; a first shielding plate provided separately from the heat insulating member between the first end portions adjacent to each other in the first direction, the intermediate portion includes a flat portion having a constant width in the first direction, The first end portion includes a narrow portion having a width smaller than that of the flat portion in the first direction, The first shielding plate is provided between the narrow portions adjacent to each other in the first direction.

2. The battery pack further includes a case for housing the plurality of battery cells. The battery pack according to claim 1 , wherein the first shielding plate is in contact with the case.

3. the first shielding plate has a first surface facing a battery cell that is located at a center in the first direction among the plurality of battery cells, and a second surface opposite to the first surface; The battery pack according to claim 1 , wherein the emissivity of the second surface is greater than the emissivity of the first surface.

4. The battery pack according to claim 1 , wherein the first shielding plate and the first end portion adjacent to each other in the first direction are spaced apart from each other.

5. The battery pack according to claim 1 , wherein in each of the plurality of separator portions, the heat insulating member and the first shielding plate are in contact with each other.

6. The battery pack according to claim 1 , wherein each of the plurality of separator portions includes a second shielding plate provided separately from the heat insulating member between the second ends adjacent to each other in the first direction.

7. The battery pack according to claim 1 or 2, wherein the battery pack is mounted on a rover that travels on a lunar surface.

8. A vehicle equipped with the battery pack according to claim 1.

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