Battery pack

Abstract

To provide a battery pack capable of suppressing a decrease in battery capacity.SOLUTION: A battery pack 1 includes: a battery module 3 formed from one cell 3a or formed by arranging a plurality of cells 3a in a line while being electrically connected; a battery case 20 that houses the battery module 3; and an intervening member 10 having a plate-shaped intervening plate 12 arranged between an outer surface 3b of the battery module 3 and an inner surface 20b of the battery case 20, a plurality of inner pieces 14 extending in a direction from the intervening plate 12 toward the battery module 3, and a plurality of connecting pieces 16 located in a direction away from the battery module 3 with respect to the intervening plate 12 and connected to the intervening plate 12. The intervening member 10 is formed with a plurality of inner compartments 14a partitioned by the plurality of inner pieces 14 and open on the side of the battery module 3, and a plurality of outer compartments 16a partitioned by the plurality of connecting pieces 16.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] In recent years, automobiles equipped with a motor as a driving source (such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), and fuel cell electric vehicles (FCEVs)) have become widespread. These automobiles (hereinafter collectively referred to as "electric vehicles") are equipped with a battery pack having a battery that supplies power to the motor and other components.

[0003] Patent Document 1 discloses a battery pack (referred to as a high-temperature battery insulated container) in which a battery module having six sides is housed in a heat-insulating container, with multiple cells being electrically connected in parallel. The cells disclosed in Patent Document 1 are composed of cylindrical single cells. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-283216 Summary of the Invention [Problem to be solved by the invention]

[0005] In the battery pack disclosed in Patent Document 1, if a space is generated between the battery module and the insulating container due to the cylindrical shape of the cells or due to variations, a temperature difference occurs in the space between the periphery of the battery module in the battery pack and the inner surface of the insulating container due to heat generation from the battery module, and a strong convection current, which is the flow of air, occurs in the space. As a result, there is a problem that the convection current and the heat exchange between the cells become active, promoting fluctuations in the cell temperature, which reduces the battery capacity and shortens the cruising distance.

[0006] Therefore, there is a demand for a battery pack that can suppress the decrease in battery capacity. [Means for solving the problem]

[0007] A characteristic configuration of a battery pack according to the present invention is that it comprises a battery module composed of one cell or composed of a plurality of cells arranged side by side and electrically connected, a battery case that houses the battery module, and an intervening member having a plate-shaped intervening plate arranged between the outer surface of the battery module and the inner surface of the battery case, a plurality of inner pieces extending from the intervening plate in a direction toward the battery module, and a plurality of connecting pieces located in a direction away from the intervening plate and connected to the intervening plate, wherein the intervening member is formed with a plurality of inner compartments partitioned by the plurality of inner pieces and open on the side of the battery module, and a plurality of outer compartments partitioned by the plurality of connecting pieces.

[0008] In this configuration, the interposition member disposed between the outer surface of the battery module and the inner surface of the battery case has an interposition plate, multiple inner pieces, and multiple connection pieces, so that even if there is a gap between the battery module and the battery case housing the battery module, it is possible to place an interposition member that is lighter than a solid interposition member in the gap.

[0009] The intervening member of this configuration is partitioned by a plurality of inner pieces, and a plurality of inner compartments that are open on the side of the battery module and a plurality of outer compartments that are partitioned by a plurality of connecting pieces are formed. The air present in the plurality of inner compartments is prevented from moving to the adjacent inner compartments by the inner pieces, and the air present in the plurality of outer compartments is prevented from moving to the adjacent outer compartments by the connecting pieces. In particular, by providing the intervening member with inner pieces and having inner compartments that are open on the side of the outer surface of the battery module, the air around the battery module can easily enter the inner compartments. As a result, in the region inside the intervening plate, the generation of convection between the air warmed by the heat generation of the cells and the cold air is prevented, and heat exchange between the convection and the cells does not occur actively. Therefore, fluctuations in the cell temperature are suppressed, and a decrease in the cruising range can be suppressed.

[0010] In this manner, the battery pack is capable of suppressing a decrease in battery capacity. [Brief description of the drawings]

[0011] [Figure 1] 1 is an exploded perspective view of a battery pack according to a first embodiment; [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. 11 is a cross-sectional view of a battery pack according to a second embodiment. [Diagram 5] FIG. 11 is a cross-sectional view of a battery pack according to a third embodiment. [Figure 6] FIG. 11 is a cross-sectional view of a battery pack according to a fourth embodiment. [Figure 7] FIG. 13 is a cross-sectional view of a battery pack according to a fifth embodiment. [Figure 8] FIG. 13 is a cross-sectional view of a battery pack according to a sixth embodiment. [Figure 9] FIG. 13 is a cross-sectional view of a battery pack according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of a battery pack according to the present invention will be described in detail with reference to the drawings. Note that the embodiments described below are merely examples for explaining the present invention, and the present invention is not limited to these embodiments. Therefore, the present invention can be embodied in various forms without departing from the gist of the present invention.

[0013] [First embodiment] 1 and 2, a battery pack 1 of this embodiment is configured by housing a battery module 3 in a case 20 (an example of a battery case) and an interposition member 10 disposed around the battery module 3. Note that although the battery pack 1 is usually configured by electrically connecting a plurality of battery modules 3, for ease of understanding, only one battery module 3 is shown in the figure.

[0014] The battery module 3 is configured by arranging a plurality of (10 in this embodiment) rectangular parallelepiped-shaped cells 3a in a line while electrically connecting them. The battery module 3 also has a rectangular parallelepiped shape. Hereinafter, each of the six faces of the battery module 3 as a whole will be referred to as an outer face 3b. The battery module 3 is a chargeable and dischargeable battery (secondary battery) such as a nickel-metal hydride battery or a lithium-ion battery. The cells 3a may have a cylindrical shape or the like other than a rectangular parallelepiped shape. The battery module 3 may also be configured with one cell 3a. In other words, the battery module 3 is configured with any number of cells 3a greater than or equal to one.

[0015] The case 20 is composed of a rectangular tubular frame plate 22 having an external shape of a rectangular parallelepiped with openings at the top and bottom, a lower plate 24 arranged to close the lower opening of the frame plate 22, and an upper plate 26 arranged to close the upper opening of the frame plate 22. The frame plate 22, the lower plate 24, and the upper plate 26 are all made of metal such as iron or aluminum, or resin such as CFPR (Carbon Fiber Reinforced Plastics). By joining the frame plate 22, the lower plate 24, and the upper plate 26, a space separated from the outside is formed inside the case 20. The battery module 3 and the interposition member 10 are accommodated in this space. Hereinafter, the four faces of the frame plate 22 facing the battery module 3 are referred to as side faces 22a, the face of the lower plate 24 facing the battery module 3 is referred to as the lower face 24a, and the face of the upper plate 26 facing the battery module 3 is referred to as the upper face 26a. Each of the six outer surfaces 3b of the battery module 3 faces one of the four side surfaces 22a, the bottom surface 24a, and the top surface 26a. The four side surfaces 22a, the bottom surface 24a, and the top surface 26a are collectively referred to as the six inner surfaces 20b of the case 20. In other words, each of the six outer surfaces 3b of the battery module 3 faces one of the six inner surfaces 20b of the case 20.

[0016] In the battery pack 1 of this embodiment, the intervening member 10 is disposed between the six outer surfaces 3b of the battery module 3 and the six inner surfaces 20b of the case 20 facing the battery module 3. That is, in a state where the battery pack 1 is housed in the case 20, there is a gap 20a (see FIG. 3) between the six outer surfaces 3b of the battery module 3 and the six inner surfaces 20b of the case 20, and the six outer surfaces 3b of the battery module 3 are separated from the six inner surfaces 20b of the case 20. The gap 20a is a part of the space. As shown in FIG. 3, a support portion 28 supported by a protruding portion 22b protruding from a side surface 22a of the frame plate 22 toward the space is disposed between the battery module 3 and the lower plate 24 located vertically below the battery module 3, and the battery module 3 is placed and supported on the support portion 28. As a result, a gap 20a in which the intervening member 10 can be disposed is formed between the outer surface 3b of the battery module 3 and the lower surface 24a of the lower plate 24. That is, the interposition member 10 disposed between the outer surface 3b of the battery module 3 and the lower surface 24a of the lower plate 24 is, to be precise, disposed between the support portion 28 and the lower surface 24a. Note that illustration of the protrusions 22b and the support portion 28 is omitted in Figs. 1 and 2.

[0017] The protruding portion 22b protrudes into the space from two opposing surfaces among the side surfaces 22a of the frame plate 22, and is formed with a female screw for fixing the support portion 28. The support portion 28 is composed of a fixing portion 28a and a support plate 28b. An end of the support plate 28b is embedded in and held by the fixing portion 28a. As a result, the fixing portion 28a and the support plate 28b are integrated as the support portion 28. A through hole is formed in the fixing portion 28a, and a bolt 28c is inserted into the through hole and screwed into the female screw of the protruding portion 22b, thereby fixing the support portion 28 to the protruding portion 22b. The support plate 28b is formed with a plurality of flow paths 28d (three in this embodiment) through which cooling water for cooling the battery module 3 flows.

[0018] As shown in FIG. 1, the interposition member 10 of this embodiment is divided into six pieces, each of which faces one of the six outer surfaces 3b of the battery module 3. The six interposition members 10 have the same configuration, except for their different sizes. Specifically, the interposition member 10 has a plate-shaped interposition plate 12, a plurality of inner pieces 14 extending from the interposition plate 12 toward the outer surface 3b of the battery module 3, and a plurality of outer pieces 16 (an example of a connection piece) extending in a direction toward the inner surface 20b of the case 20 relative to the interposition plate 12, i.e., in a direction away from the outer surface 3b of the battery module 3. In other words, the plurality of outer pieces 16 are located in a direction away from the outer surface 3b of the battery module 3 relative to the interposition plate 12, and are connected to the interposition plate 12. Hereinafter, in the gap 20a divided into two by the intervening plate 12, the side where the inner piece 14 extends will be referred to as the inner region 20c, and the side where the outer piece 16 extends will be referred to as the outer region 20d (see FIG. 3). Note that the material used for the intervening member 10 is preferably a heat insulating material or resin having a lower thermal conductivity than the case 20. However, the intervening member 10 does not necessarily need to be made of a material having a lower thermal conductivity than the case 20, and may be made of a material having a higher thermal conductivity than the case 20.

[0019] The intervening plate 12 covers the battery module 3 in a position along the outer surface 3b of the battery module 3. The intervening plate 12 is arranged so that the distance between the intervening plate 12 and the case 20 is longer than the distance between the intervening plate 12 and the battery module 3. In other words, the intervening plate 12 is arranged closer to the outer surface 3b of the battery module 3 than the inner surface 20b of the case 20. The multiple inner pieces 14 and the multiple outer pieces 16 extend in opposite directions from the same position of the intervening plate 12 so as to form a lattice. As a result, the inner region 20c of the case 20 is partitioned into multiple small rectangular parallelepiped spaces surrounded by the intervening plate 12 and the four inner pieces 14, and the outer region 20d is partitioned into multiple small rectangular parallelepiped spaces surrounded by the intervening plate 12 and the four outer pieces 16. Hereinafter, in the intervening member 10, the multiple small rectangular parallelepiped spaces surrounded by the intervening plate 12 and the four inner pieces 14 are referred to as inner compartments 14a. Similarly, in the interposition member 10, the multiple small rectangular parallelepiped spaces surrounded by the interposition plate 12 and the four outer pieces 16 are referred to as outer compartments 16a. In other words, the inner compartment 14a is part of the inner region 20c, and the outer compartment 16a is part of the outer region 20d.

[0020] In this manner, if multiple inner compartments 14a are arranged side by side, the air present in the multiple inner compartments 14a can be reliably prevented from moving to the adjacent inner compartments 14a by the inner piece 14. Also, if multiple outer compartments 16a are arranged side by side, the air present in the multiple outer compartments 16a can be reliably prevented from moving to the adjacent outer compartments 16a by the outer piece 16. As a result, temperature fluctuations within the same plane of the cells 3a are suppressed, and it is possible to suppress a decrease in the battery capacity of the battery pack 1.

[0021] In this embodiment, the inner chambers 14a and the outer chambers 16a are both rectangular parallelepiped spaces, and therefore, when viewed from a direction perpendicular to the intervening plate 12 (hereinafter, also referred to as a vertical view), they are all rectangular. However, the inner chambers 14a and the outer chambers 16a are not limited to a rectangular shape when viewed in the vertical direction, and may be a triangular shape or a polygonal shape having pentagons or more. By configuring the inner chambers 14a and the outer chambers 16a to be polygonal when viewed in the vertical direction, the inner chambers 14a and the outer chambers 16a can be arranged side by side without gaps. The "polygonal shape" is not limited to a shape with bent corners, but also includes a shape that is curved and has a corner R. The shape of the inner chambers 14a and the outer chambers 16a when viewed in the vertical direction can be any shape as long as it can partition the gap 20a (the inner region 20c and the outer region 20d). Furthermore, the polygonal shape of the inner compartment 14a when viewed in the vertical direction and the polygonal shape of the outer compartment 16a when viewed in the vertical direction may be configured to be different polygonal shapes (for example, a rectangular shape and a hexagonal shape).

[0022] In this embodiment, the length of the outer piece 16 in the direction extending from the intervening plate 12 (the height of the outer piece 16 from the intervening plate 12) is longer than the length of the inner piece 14 in the direction extending from the intervening plate 12 (the height of the inner piece 14 from the intervening plate 12). Therefore, the volume of each of the outer compartments 16a is larger than the volume of each of the inner compartments 14a. In this way, if the outer piece 16 is made longer than the inner piece 14, the volume of the inner compartment 14a is reduced, so that convection in the inner compartment 14a, in which the air is likely to change in temperature due to heat generated by the cells 3a, can be further suppressed. As a result, temperature fluctuations within the same plane of the cells 3a are suppressed, and it is possible to suppress a decrease in the battery capacity of the battery module 3.

[0023] In FIG. 1, the length of each of the outer pieces 16 in the direction extending from the intervening plate 12 (the height of the outer pieces 16 from the intervening plate 12) is the same, and the length of each of the inner pieces 14 in the direction extending from the intervening plate 12 (the height of the inner pieces 14 from the intervening plate 12) is the same. Therefore, the volumes of the outer compartments 16a are the same, and the volumes of the inner compartments 14a are the same. However, in reality, as shown in FIG. 3, the surface of the support portion 28 facing the intervening member 10 has unevenness, and the surface of the battery module 3 also has unevenness (not shown). In this embodiment, as described later, in each of the six intervening members 10, the inner pieces 14 are in contact with the outer surface 3b of the battery module 3 and the support portion 28. Therefore, the actual length of the inner piece 14 is set to a length that follows the unevenness of the outer surface 3b of the battery module 3 and the surface of the support portion 28.

[0024] In this embodiment, as shown in FIG. 3, each of the six interposition members 10 is arranged such that the inner pieces 14 are in contact with the outer surface 3b of the battery module 3 and the support portion 28, and the outer pieces 16 are spaced apart from the inner surface 20b of the case 20. That is, the inner compartment 14a is partitioned by the inner pieces 14 and the adjacent inner compartments 14a. Meanwhile, the outer compartments 16a are partitioned by the outer pieces 16 and are connected to the adjacent outer compartments 16a through gaps 20a (outer regions 20d). To bring the inner pieces 14 of the interposition member 10 into contact with the outer surface 3b of the battery module 3 and to separate the outer pieces 16 from the inner surface 20b of the case 20, for example, the inner pieces 14 can be fixed to the outer surface 3b of the battery module 3 with an adhesive, or a cylindrical support (not shown) can be protruded from a part of the outer piece 16 so as to come into contact with the inner surface 20b of the case 20 while the inner pieces 14 are in contact with the outer surface 3b. In this manner, if the multiple inner pieces 14 are in contact with the outer surface 3b, the air present in the multiple inner compartments 14a can be reliably prevented from moving to adjacent inner compartments 14a by the inner pieces 14. As a result, temperature fluctuations within the same surface of the cells 3a are suppressed, and it is possible to suppress a decrease in the battery capacity of the battery pack 1.

[0025] Second Embodiment Next, a battery pack 1 according to a second embodiment will be described with reference to Fig. 4. In this embodiment, the six interposition members 10 are all different from the first embodiment in that the outer pieces 16 are in contact with the inner surface 20b of the case 20, and the inner pieces 14 are arranged so as to be spaced apart from the outer surface 3b of the battery module 3 and the support portion 28. Other than that, the configuration is the same as that of the first embodiment. Therefore, in the description of this embodiment, the same reference numerals are used for the parts having the same configuration as the first embodiment, and detailed description of the same configuration is omitted.

[0026] The air warmed by the heat generated by the cells 3a flows upward along the outer surface 3b of the battery module 3, so there is relatively little effect of convection on the outer surface 3b of the battery module 3. For this reason, if the multiple inner pieces 14 are spaced apart from the six outer surfaces 3b as in this configuration, it is possible to simplify the structure and prioritize the effect of reducing material costs.

[0027] Third Embodiment Next, a battery pack 1 according to a third embodiment will be described with reference to Fig. 5. In this embodiment, the six interposition members 10 are arranged such that the outer pieces 16 are in contact with the inner surface 20b of the case 20, and the inner pieces 14 are in contact with the outer surface 3b of the battery module 3 and the support portion 28. Other than that, the battery pack 1 according to the third embodiment has the same configuration as the first and second embodiments. Therefore, in the description of this embodiment, the same reference numerals are used for the parts having the same configuration as the first and second embodiments, and detailed description of the same configuration is omitted.

[0028] If the multiple inner pieces 14 are in contact with the outer surface 3b, the air present in the multiple inner compartments 14a can be reliably prevented from moving to the adjacent inner compartments 14a by the inner pieces 14. Also, if the multiple outer pieces 16 are in contact with the inner surface 20b, the air present in the multiple outer compartments 16a can be reliably prevented from moving to the adjacent outer compartments 16a by the outer pieces 16. As a result, temperature fluctuations within the same surface of the cells 3a are suppressed, and it is possible to suppress a decrease in the battery capacity of the battery pack 1. Also, since the intervening member 10 can be fixed simply by inserting it into the gap 20a, there is no need to use an adhesive for fixing, and the number of steps can be reduced.

[0029] [Other embodiments in addition to the first to third embodiments] (a) Two opposing surfaces of the frame plate 22 of the case 20 may be configured as energy absorbing parts. In other words, a frame member in the left-right direction of the vehicle may be used as the energy absorbing part, which is the frame plate 22. The energy absorbing part has a function of absorbing an external force, such as an impact, acting on the battery pack 1 and suppressing the external force from being transmitted to the battery module 3.

[0030] (b) In each of the above embodiments, the multiple inner pieces 14 and the multiple outer pieces 16 extend in opposite directions from the same position on the intervening plate 12, but they may extend in opposite directions from different positions on the intervening plate 12. In this case, the area of ​​one inner compartment 14a and the area of ​​one outer compartment 16a when viewed from a direction perpendicular to the intervening plate 12 will be different, and it is preferable that the number of inner compartments 14a be greater than the number of outer compartments 16a.

[0031] (c) In each of the above embodiments, the case 20 is formed by joining three parts, the frame plate 22, the lower plate 24, and the upper plate 26, but this is not limited thereto. The case 20 may be formed, for example, by two parts in which the frame plate 22 and the lower plate 24 are integrated and the upper plate 26 is joined, or by two parts in which the frame plate 22 and the upper plate 26 are integrated and the lower plate 24 is joined. Furthermore, the case 20 may be formed by two parts in which the frame plate 22 and the lower plate 24 are integrated and the frame plate 22 and the upper plate 26 are integrated and joined. In this case, the height of the frame plate 22 can be halved. That is, the case 20 can be formed by two parts of any shape. The case 20 may also be formed by four or more parts.

[0032] (d) In the above embodiments, the interposing members 10 are disposed between all of the outer surfaces 3b of the battery module 3 and all of the inner surfaces 20b of the case 20, but this is not limited thereto. The interposing members 10 may be disposed only in one or more locations where it is necessary to suppress air convection between the case 20 and the battery module 3. This configuration makes it possible to reduce the number of interposing members 10 used, and allows the battery pack 1 to be manufactured at low cost.

[0033] (e) In each of the above embodiments, when a plurality of (six in the above embodiment) intervening members 10 are arranged, all six intervening members 10 have the same configuration. That is, in the first embodiment, the plurality of inner pieces 14 of all intervening members 10 are arranged so as to abut against the outer surface 3b of the battery module 3 and the support portion 28, and the plurality of outer pieces 16 are arranged so as to be spaced apart from the inner surface 20b of the case 20. In the second embodiment, the plurality of outer pieces 16 are arranged so as to abut against the inner surface 20b of the case 20, and the plurality of inner pieces 14 are arranged so as to be spaced apart from the outer surface 3b of the battery module 3 and the support portion 28. Furthermore, in the third embodiment, the plurality of outer pieces 16 are arranged so as to abut against the inner surface 20b of the case 20, and the plurality of inner pieces 14 are arranged so as to abut against the outer surface 3b of the battery module 3 and the support portion 28. However, when multiple intervening members 10 are disposed between the outer surface 3b of the battery module 3 and the inner surface 20b of the case 20, some intervening members 10 may be disposed as in the first embodiment, and other intervening members 10 may be disposed as in the second embodiment. In other words, as long as air convection between the case 20 and the battery module 3 can be effectively suppressed, an optimal arrangement among the first to third embodiments can be adopted for each of the multiple intervening members 10.

[0034] (f) In each of the above embodiments, the multiple inner compartments 14a and the multiple outer compartments 16a are polygonal in shape when viewed in the vertical direction, but this is not limited to the above. The multiple inner compartments 14a and the multiple outer compartments 16a may be circular (including elliptical and oval) in shape when viewed in the vertical direction. In addition, either or both of the multiple inner compartments 14a and the multiple outer compartments 16a may have both polygonal and circular compartments when viewed in the vertical direction.

[0035] [Fourth embodiment] Next, a battery pack 1 according to a fourth embodiment will be described with reference to Fig. 6. This embodiment differs from the second embodiment in that it includes a plate member 42. Other than that, it has the same configuration as the second embodiment. Therefore, in the description of this embodiment, the same reference numerals are used for the parts having the same configuration as the second embodiment, and detailed description of the same configuration will be omitted.

[0036] In this embodiment, at least one plate member 42 is provided between the intervening plate 12 and the inner surface 20b of the case 20. The plate member 42 has a plate material 30, and the plate material 30 is provided with a plurality of protruding pieces 32 extending in a direction away from the battery module 3 with respect to the plate material 30. That is, the protruding pieces 32 are provided on a surface of the protruding pieces 32 facing the inner surface 20b of the case 20 so as to extend toward the inner surface 20b. On the other hand, the surface of the plate material 30 facing the outer surface 3b of the battery module 3 is configured without being provided with any protruding pieces 32.

[0037] Here, also in this embodiment, a plurality of rectangular parallelepiped outer compartments 16a are formed in the intervening member 10 by the intervening plate 12 and the plurality of outer pieces 16. The plate material 30 is provided in a state where it is sandwiched between the intervening plate 12 and the inner surface 20b of the case 20 within the case 20. As a result, the outer compartments 16a are formed as sealed spaces between the intervening plate 12 and the outer pieces 16 of the intervening member 10 and the plate material 30. Therefore, most of the battery module 3 is surrounded by a sealed space between the case 20, and therefore, it is possible to further restrict the air present in each of the plurality of outer compartments 16a from moving to the adjacent outer compartments 16a.

[0038] Furthermore, a compartment 34 is formed by the plate material 30, the protruding piece 32, and the inner surface 20b of the case 20, and together with the outer compartment 16a described above, it is possible to further improve the air insulation performance against the outside air.

[0039] In this manner, in this embodiment, by making each of the outer compartments 16a a sealed space, the movement of air in each of the outer compartments 16a is restricted and the air insulation performance against the outside air is further improved. Therefore, the thickness of the intervening plate 12 can be configured to be greater than the thickness of the plate material 30. In other words, the thickness of the plate material 30 can be configured to be smaller than the thickness of the intervening plate 12. As a result, even when the plate material 30 is provided, the weight of the battery pack 1 can be reduced compared to a case in which the thickness of the plate material 30 is configured to be the same as the thickness of the intervening plate 12.

[0040] In this configuration, the intervening plate 12, the inner piece 14, and the outer piece 16 may be integrally formed as the intervening member 10, and the plate material 30 and the protruding piece 32 may be integrally formed as the plate member 42. Furthermore, the intervening member 10 and the plate member 42 may be integrated by joining the outer piece 16 and the plate material 30 to each other. This increases the sealing degree of the outer compartment 16a described above, and makes it possible to further restrict the movement of air in each of the outer compartments 16a and to improve the air insulation performance against the outside air. The outer piece 16 and the plate material 30 may be joined together using, for example, an adhesive or by fastening and fixing using bolts.

[0041] In this embodiment, the number of inner pieces 14 is greater than the number of outer pieces 16 and protruding pieces 32. That is, the number of inner compartments 14a is greater than the number of outer compartments 16a. This allows the inner compartments 14a to be small, so that it is possible to further suppress the occurrence of convection between the air warmed by heat generation from the cells 3a and the cold air in the region 20c inside the intermediate plate 12.

[0042] Fifth embodiment Next, a battery pack 1 according to a fifth embodiment will be described with reference to Fig. 7. This embodiment differs from the fourth embodiment in that the interposition member 10 and the plate member 42 are not provided between the battery module 3 and the lower plate 24. Other than that, the configuration is the same as that of the fourth embodiment. Therefore, in the description of this embodiment, the same reference numerals are used for the parts having the same configuration as the fourth embodiment, and detailed description of the same configuration is omitted.

[0043] As described above, in the battery pack 1 of the present embodiment, the intervening member 10 and the plate member 42 are not provided between the battery module 3 and the lower plate 24, and the battery module 3 is configured with a gap between it and the lower surface 24a of the case 20. Since heat from the battery module 3 moves to the upper plate 26 side, it is not necessary to provide the intervening member 10 and the plate member 42 between the battery module 3 and the lower plate 24. This makes it possible to reduce weight and costs. The battery module 3 may be configured with no gap between it and the lower surface 24a of the case 20, that is, with the battery module 3 placed on the lower plate 24 of the case 20.

[0044] Sixth Embodiment Next, a battery pack 1 according to a sixth embodiment will be described with reference to Fig. 8. This embodiment differs from the fourth embodiment in that only a plate member 42 is provided between the battery module 3 and the lower plate 24, and no intervening member 10 is provided. Other than that, the configuration is the same as that of the fourth embodiment. Therefore, in the description of this embodiment, the same reference numerals are used for parts having the same configuration as the fourth embodiment, and detailed description of the same configuration will be omitted.

[0045] As described above, in the battery pack 1 of the present embodiment, the plate member 42 is provided between the battery module 3 and the lower plate 24, but no intervening member 10 is provided. The battery module 3 is configured with a gap between it and the plate member 42. The compartment 34 formed by the plate member 42, the protruding piece 32, and the lower plate 24 makes it possible to suppress air convection on the lower plate 24 side.

[0046] Seventh embodiment Next, a battery pack 1 according to a sixth embodiment will be described with reference to Fig. 9. This embodiment differs from the fourth embodiment in that a plurality of plate members 42 are provided between the battery module 3 and the inner surface 20b of the case 20.

[0047] In this embodiment, two plate members 42 are stacked between the battery module 3 and the inner surface 20b of the case 20. As in the fourth embodiment, the plate material 30 of each plate member 42 is provided with a plurality of protruding pieces 32 in a direction away from the outer surface 3b of the battery module 3. Therefore, among the two plate members 42 stacked on each other, the plate material 30 of the plate member 42 on the outer surface 3b side of the battery module 3, the protruding pieces 32 of the plate member 42, and the plate material 30 of the plate member 42 on the inner surface 20b side of the case 20 form a compartment 36. As a result, the inner compartment 14a, the outer compartment 16a, the compartment 36, and the compartment 34 are provided from the outer surface 3b side of the battery module 3, thereby improving the air insulation performance and making it possible to further enhance the effect of suppressing air convection.

[0048] [Other embodiments in addition to the fourth to seventh embodiments] (a) The number of inner pieces 14 may be the same as the number of outer pieces 16 and protruding pieces 32, or may be less than the number of outer pieces 16 and protruding pieces 32. Also, in the battery packs 1 of the first, second, and third embodiments, the number of inner pieces 14 may be greater than the number of outer pieces 16.

[0049] (b) The thickness of the intermediate plate 12 may be the same as the thickness of the plate material 30 or may be smaller than the thickness of the plate material 30 .

[0050] (c) The intervening plate 12, the inner piece 14, and the outer piece 16 do not have to be integrally formed. Also, the plate material 30 and the protruding piece 32 do not have to be integrally formed. Furthermore, the intervening member 10 and the plate member 42 do not have to be joined to the outer piece 16 and the plate material 30, and may be in a state of contact with each other. If possible, the intervening plate 12, the inner piece 14, the outer piece 16, the plate material 30, and the protruding piece 32 are integrally formed to increase assembly efficiency.

[0051] (d) In the above-described embodiment, the protruding piece 32 protruding from the plate material 30 toward the battery module 3 side is not provided, but a piece (not shown) protruding from the plate material 30 toward the battery module 3 side may be provided, and this piece may be configured as a connection piece connected to the intervening plate 12. Also, the piece protruding from the plate material 30 toward the battery module 3 side may be connected to the outer piece 16 to form a connection piece connected to the intervening plate 12. In other words, the number of connection pieces connected to the intervening plate 12 may be one or more pieces formed between the intervening plate 12 and the plate material 30. As a result, the sealed space is created by any of (a) a space surrounded by the intervening plate 12, the outer piece 16, and the plate material 30, (b) a space surrounded by the intervening plate 12, the piece protruding from the plate material 30 toward the battery module 3 side, and the plate material 30, or (c) a space surrounded by the intervening plate 12, the outer piece 16, the piece protruding from the plate material 30 toward the battery module 3 side, and the plate material 30.

[0052] In the above-described embodiment, the following configurations are envisaged. <1> a battery case (20) for accommodating the battery module (3); and an interposition member (10) having a plate-shaped interposition plate (12) arranged between an outer surface (3b) of the battery module (3) and an inner surface (20b) of the battery case (20), a plurality of inner pieces (14) extending from the interposition plate (12) toward the battery module (3), and a plurality of connecting pieces (16) located in a direction away from the interposition plate (12) and connected to the interposition plate (12), wherein the interposition member (10) is formed with a plurality of inner compartments (14a) partitioned by the plurality of inner pieces (14) and open on the side of the battery module (3), and a plurality of outer compartments (16a) partitioned by the plurality of connecting pieces (16).

[0053] In this configuration, the interposition member (10) disposed between the outer surface (3b) of the battery module (3) and the inner surface (20b) of the battery case (20) has an interposition plate (12), a plurality of inner pieces (14), and a plurality of connection pieces (16). Therefore, even if a gap (20a) exists between the battery module (3) and the battery case (20) housing the battery module (3), it is possible to dispose the interposition member (10), which is lighter than a solid interposition member, in the gap (20a).

[0054] The interposition member (10) of this configuration is formed with a plurality of inner compartments (14a) partitioned by a plurality of inner pieces (14) and open on the side of the battery modules (3), and a plurality of outer compartments (16a) partitioned by a plurality of connecting pieces (16). The inner pieces (14) prevent air present in the inner compartments (14a) from moving to the adjacent inner compartments (14a), and the connecting pieces (16) prevent air present in the outer compartments (16a) from moving to the adjacent outer compartments (16a). In particular, by providing the interposition member (10) with the inner pieces (14) and by providing the plurality of inner compartments (14a) open on the side facing the outer surface (3b) of the battery modules (3), air around the battery modules (3) can easily enter the inner compartments (14a). As a result, in the region (20c) inside the intervening plate (12), the generation of convection between the air warmed by the heat generated by the cells (3a) and the cold air is suppressed, and heat exchange between the convection and the cells (3a) does not actively occur, thereby suppressing fluctuations in the cell temperature and reducing the reduction in the cruising distance.

[0055] <2> <1> In the battery pack (1) described above, the inner compartment (14a) has a polygonal shape when viewed from a direction perpendicular to the intervening plate (12), and a plurality of the inner compartments (14a) are arranged side by side.

[0056] If the inner compartments (14a) have a polygonal shape when viewed perpendicularly to the intervening plate (12) as in this configuration, the inner compartments (14a) can be arranged side by side with no gaps. Furthermore, if the inner compartments (14a) are arranged side by side, the inner piece (14) can reliably prevent the air present in the inner compartments (14a) from moving to the adjacent inner compartments (14a). As a result, temperature fluctuations within the same plane of the cells (3a) are suppressed, and it is possible to suppress a decrease in the battery capacity of the battery pack (1).

[0057] <3> <1> In the battery pack (1) described in the above, the multiple inner pieces (14) are spaced apart from the battery module (3), and the multiple connection pieces (16) are in contact with the battery case (20).

[0058] Since the air heated by the heat generated by the cells (3a) flows upward along the outer surface (3b) of the battery module (3), the surface (3b) of the battery module (3) is relatively less affected by convection. Therefore, if the multiple inner pieces (14) are spaced apart from the battery module (3) as in this configuration, it is possible to simplify the structure and prioritize the effect of reducing material costs. In addition, since the multiple connection pieces (16) abut against the battery case (20), it is possible to reliably prevent the air present in the multiple outer compartments (16a) from moving to adjacent outer compartments (16a).

[0059] <4> <1> from <3> In the battery pack (1) described in any one of the above, the distance between the intervening plate (12) and the battery case (20) is longer than the distance between the intervening plate (12) and the battery module (3), and the connecting piece (16) is longer than the inner piece (14).

[0060] In this configuration, by making the distance between the interposer plate (12) and the battery case (20) longer than the distance between the interposer plate (12) and the battery module (3) and by making the connecting piece (16) longer than the inner piece (14), the volume of the inner compartment (14a) becomes smaller than the volume of the outer compartment (16a), and this makes it possible to further suppress convection in the inner compartment (14a) where the air is susceptible to temperature changes due to heat generated by the cells (3a). As a result, temperature fluctuations within the same plane of the cells (3a) are suppressed, making it possible to suppress a decrease in battery capacity.

[0061] <5> <1> The battery pack (1) described in the above item (1) further includes at least one plate member (30) between the intervening plate (12) and the inner surface (20b) of the battery case (20), an outer compartment (16a) is formed as an enclosed space between the intervening plate (12) of the intervening member (10), the connecting piece (16), and the plate member (30), and the plate member (30) is provided with a plurality of protruding pieces (32) extending in a direction away from the battery module (3).

[0062] According to this configuration, most of the battery module (3) is surrounded by a sealed space between the battery case (20), which further prevents air in each of the outer compartments (16a) from moving to an adjacent outer compartment (16a). In addition, the plate material (30), the protruding piece (32), and the inner surface (20b) of the battery case (20) can further improve air insulation performance against outside air.

[0063] <6> <1> or <5> In the battery pack (1) described above, the number of inner compartments (14a) is greater than the number of outer compartments (16a).

[0064] According to this configuration, the number of the inner compartments (14a) is greater than the number of the outer compartments (16a), so that it is possible to further suppress the occurrence of convection between the air warmed by the heat generated by the cells (3a) and the cold air in the region (20c) inside the intermediate plate (12).

[0065] <7> <1> or <5> In the battery pack (1) described above, the number of inner pieces (14) is greater than the number of connecting pieces (16).

[0066] This configuration allows the inner compartment (14a) to be divided into smaller compartments on the outer surface (3b) side of the battery module (3) relative to the intervening plate (12). This makes it possible to further suppress the occurrence of convection between the air warmed by heat generated by the cells (3a) and the cold air in the region (20c) on the inner side of the intervening plate (12).

[0067] <8> <5> In the battery pack (1) described above, the thickness of the intervening plate (12) is configured to be greater than the thickness of the plate material (30).

[0068] This configuration makes it possible to suppress an increase in the amount of material used for the plate material (30) even when the plate material (30) is provided, and therefore makes it possible to suppress an increase in the weight and cost of the battery pack (1) even when the plate material (30) is provided.

[0069] <9> <1> In the battery pack (1) described above, the intervening plate (12), the inner piece (14), and the connecting piece (16) are integrally formed to constitute the intervening member (10), the plate material (30) and the protruding piece (32) are integrally formed to constitute the plate member (42), and the intervening member (10) and the plate member (42) are integrated by joining the connecting piece (16) and the plate material (30) to each other.

[0070] This configuration increases the degree of sealing of the outer compartments (16a), making it possible to further restrict the movement of air in each of the outer compartments (16a) and to further improve the air insulation performance against outside air. [Industrial Applicability]

[0071] The present invention can be used in a battery pack. [Explanation of symbols]

[0072] 1: battery pack, 3: battery module, 3a: cell, 3b: outer surface, 10: intervening member, 12: intervening plate, 14: inner piece, 14a: inner compartment, 16: outer piece (connecting piece), 16a: outer compartment, 20: case (battery case), 30: plate material, 32: protruding piece, 36: compartment (sealed space), 42: plate member

Claims

1. a battery module configured by one cell or by arranging a plurality of cells in a line while being electrically connected to each other; a battery case that houses the battery module; an interposition member including a plate-shaped interposition plate disposed between an outer surface of the battery module and an inner surface of the battery case, a plurality of inner pieces extending from the interposition plate in a direction toward the battery module, and a plurality of connection pieces positioned in a direction away from the interposition plate and connected to the interposition plate, The intervening member is a battery pack having a plurality of inner compartments partitioned by a plurality of the inner pieces and open on the side of the battery module, and a plurality of outer compartments partitioned by a plurality of the connecting pieces.

2. 2. The battery pack according to claim 1, wherein the inner compartment has a polygonal shape when viewed from a direction perpendicular to the intervening plate, and a plurality of the inner compartments are arranged side by side.

3. The battery pack according to claim 1 , wherein the inner pieces are spaced apart from the battery module, and the connection pieces are in contact with the battery case.

4. The battery pack according to claim 1 , wherein a distance between the intermediate plate and the battery case is longer than a distance between the intermediate plate and the battery module, and the connection piece is longer than the inner piece.

5. At least one plate material is further provided between the intermediate plate and the inner surface of the battery case, The outer compartment is formed as a sealed space between the intermediate plate of the intermediate member, the connection piece, and the plate material, The battery pack according to claim 1 , wherein the plate member is provided with a plurality of protruding pieces extending in a direction away from the battery module.

6. 6. The battery pack according to claim 1, wherein the number of said inner compartments is greater than the number of said outer compartments.

7. The battery pack according to claim 1 or 5, wherein the number of the inner pieces is greater than the number of the connection pieces.

8. The battery pack according to claim 5 , wherein the thickness of the intermediate plate is greater than the thickness of the plate material.

9. the intermediate plate, the inner piece, and the connecting piece are integrally formed to constitute the intermediate member, The plate member is configured by integrally forming the plate material and the protruding piece, The battery pack according to claim 5 , wherein the intermediate member and the plate member are integrated by joining the connection piece and the plate member to each other.

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