Battery

Abstract

To obtain a battery with improved heat dissipation. [Solution] A battery 10 comprising an outer casing 20 having a rectangular flat bottom wall 22 and a pair of main body walls 24 integrally erected on the long sides of the bottom wall 22, an electrode body 12 housed in the outer casing 20, a lid 30 provided between the ends of the pair of main body walls 24 opposite to the bottom wall 22, a first thermal conductive material 28 provided on the inner surface of the bottom wall 22, and a second thermal conductive material 38 provided on the inner surface of the lid 30, wherein the thickness of the bottom wall 22 is thinner than the thickness of the lid 30, and the thickness of the first thermal conductive material 28 is thicker than the thickness of the second thermal conductive material 38.

Description

Technical Field

[0001] The present invention relates to a battery.

Background Art

[0002] All-solid-state batteries that do not use an electrolyte have been conventionally known (see, for example, Patent Document 1). This all-solid-state battery is configured to dissipate heat by arranging a heat transfer material on the lower surface of an electrode laminate enclosed in an exterior member and through heat conduction from the heat transfer material through the exterior member to enhance the cooling efficiency.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, there is still room for improvement in improving the heat dissipation performance of a battery having a lid for sealing the exterior body.

[0005] Therefore, an object of the present invention is to obtain a battery capable of improving heat dissipation performance.

Means for Solving the Problems

[0006] To achieve the above object, a battery according to a first aspect of the present invention includes an exterior body having a rectangular flat bottom wall and a pair of main body walls integrally erected on the long side portions of the bottom wall, an electrode body housed in the exterior body, a lid provided between the ends of the pair of main body walls on the side opposite to the bottom wall, a first heat transfer material provided on the inner surface of the bottom wall, and a second heat transfer material provided on the inner surface of the lid, wherein the thickness of the bottom wall is thinner than the thickness of the lid, and the thickness of the first heat transfer material is thicker than the thickness of the second heat transfer material.

[0007] According to the first embodiment of the invention, the outer casing housing the electrode body has a rectangular flat bottom wall and a pair of main body walls integrally erected on the long sides of the bottom wall, and a first thermal conductive material is provided on the inner surface of the bottom wall. A lid is provided between the ends of the pair of main body walls opposite to the bottom wall, and a second thermal conductive material is provided on the inner surface of the lid. Here, the thickness of the bottom wall is thinner than the thickness of the lid, and the thickness of the first thermal conductive material is thicker than the thickness of the second thermal conductive material. Therefore, the heat dissipation of the outer casing, especially on the bottom wall side, is improved, and the battery is cooled efficiently.

[0008] Furthermore, a battery according to a second embodiment of the present invention is a battery according to the first embodiment, wherein an insulating film thinner than the second thermal conductive material is provided on the inner surface of the main body wall.

[0009] According to the second embodiment of the invention, an insulating film thinner than the second thermal conductive material is provided on the inner surface of the main body wall. Therefore, the reduction in the volumetric energy density of the electrode body is suppressed, while the outer casing and the electrode body are effectively insulated.

[0010] Furthermore, the battery according to the third embodiment of the present invention is the battery according to the first or second embodiment, wherein the main body wall is larger than the bottom wall.

[0011] According to the third embodiment of the invention, the main body wall is larger than the bottom wall. Therefore, compared to the case where the main body wall is smaller than the bottom wall, the reduction in the volumetric energy density of the electrode body is suppressed.

[0012] Furthermore, a fourth embodiment of the present invention is a battery according to any one of the first to third embodiments, wherein the electrode body has a terminal portion capable of closing the opening of the outer casing on the short side of the bottom wall.

[0013] According to the fourth embodiment of the invention, the electrode body has a terminal portion that can close the opening of the outer casing on the short side of the bottom wall. Therefore, the opening of the outer casing can be closed simply by inserting the electrode body into the outer casing, and as a result, the lid becomes easier to assemble to the outer casing. In other words, the ease of assembly between the outer casing and the lid is improved.

[0014] Furthermore, a fifth embodiment of the present invention is a battery according to any one of the first to fourth embodiments, wherein the outer casing has protruding portions that extend toward each other at the ends of the pair of main body walls opposite to the bottom wall, and the lid is formed in a "convex" shape having a narrow portion and a wide portion when viewed in cross-section from a direction along the long side of the bottom wall, the narrow portion being sandwiched by the protruding portion, and the outer surface of the narrow portion and the outer surface of the protruding portion being flush.

[0015] According to the fifth embodiment of the invention, the outer casing has protruding portions that extend toward each other at the ends of the pair of main body walls opposite to the bottom wall. The lid is formed in a "convex" shape with a narrow portion and a wide portion when viewed in cross-section from a direction along the long side of the bottom wall of the outer casing, with the narrow portion being sandwiched between the protruding portions, and the outer surfaces of the narrow portion and the protruding portions being flush. Therefore, compared to, for example, a case where the outer surface of the protruding portion protrudes more than the outer surface of the narrow portion, it becomes easier to bring a cooling member into contact with the lid when cooling the battery by bringing the cooling member into contact with the lid. Thus, the battery is cooled efficiently. [Effects of the Invention]

[0016] As described above, the present invention makes it possible to improve heat dissipation in batteries. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic perspective view showing the battery according to this embodiment. [Figure 2] This is a schematic perspective view showing the electrode body of the battery according to this embodiment. [Figure 3] This is a schematic perspective view showing the battery casing according to this embodiment. [Figure 4] It is a schematic perspective view showing the lid of the battery according to this embodiment. [Figure 5] It is a schematic cross-sectional view showing the internal structure of the battery according to this embodiment. [Figure 6] (A) to (E) are schematic process diagrams showing the manufacturing method of the battery according to this embodiment.

Embodiments for Carrying out the Invention

[0018] Hereinafter, embodiments according to the present invention will be described in detail based on the drawings. For convenience of explanation, in each figure, the arrow UP shown as appropriate is the upward direction of the battery, the arrow FR is the forward direction of the battery, and the arrow LH is the leftward direction of the battery. Therefore, in the following description, when the directions of up and down, front and back, and left and right are described without special mention, they indicate up and down, front and back, and left and right in the battery, but they are not particularly limited to these directions.

[0019] As shown in FIG. 1, the battery 10 according to this embodiment is a all-solid-state battery, and includes an electrode body 12 shown in FIG. 2, an exterior body 20 shown in FIG. 3 that houses the electrode body 12, and a lid body 30 shown in FIG. 4 that closes the upper end portion of the exterior body 20 that houses the electrode body 12 (the end portion on the side opposite to the bottom wall 22 described later). Note that the exterior body 20 and the lid body 30 are formed of a metal such as an aluminum alloy.

[0020] As shown in FIG. 2, the electrode body 12 is formed in a rectangular flat plate shape with the front-rear direction as the thickness direction. Metal terminal portions 14 are respectively attached to both the left and right side portions of the electrode body 12 in advance by welding or the like. The terminal portion 14 is formed to be slightly larger than the left and right side portions of the electrode body 12, and has a size capable of closing an opening portion 18 (described later) of the exterior body 20. Note that on the outer surface of the terminal portion 14, a pair of electrode terminals 16 having a substantially square shape and a predetermined protruding height are integrally formed at a predetermined interval in the vertical direction when viewed from the left-right direction.

[0021] As shown in FIG. 3, the exterior body 20 has a rectangular flat bottom wall 22 with the longitudinal direction being the left - right direction, and a pair of main body walls 24 standing upright integrally on the long - side portions of the bottom wall 22 respectively. The main body walls 24 are larger than the bottom wall 22, and the short - side portion side of the bottom wall 22 in the exterior body 20 is an opening 18. Also, the plate thickness (thickness) D (see FIG. 5) of the bottom wall 22 (exterior body 20) is formed thinner than the thickness H2 of the wide portion 34 of the lid body 30 to be described later (H2 > D).

[0022] Also, at the upper - end portions (the end portions on the side opposite to the bottom wall 22) of the pair of main body walls 24, overhanging portions 26 that project in directions approaching each other are integrally formed respectively. The overhanging length L of the overhanging portions 26 in the directions approaching each other is the same. That is, the narrow - width portion 32 of the lid body 30 to be described later, which seals the upper - end portion of the exterior body 20, is arranged at the center in the front - rear direction of the upper - end portion.

[0023] Also, as shown in FIG. 5, on the inner surface (upper surface) of the bottom wall 22 of the exterior body 20, a heat - conductive sheet 28 as a first heat - conductive material, which is formed with a predetermined thickness D1 (thicker than the thickness D2 of the heat - conductive sheet 38 to be described later: D1 > D2) with a silicone - based resin material over substantially the entire surface, is provided by being pasted. And on the inner surface of the main body wall 24 of the exterior body 20, an insulating film 27, which is formed with a predetermined thickness D3 (thinner than the thickness D2 of the heat - conductive sheet 38 to be described later: D2 > D3) with a non - stretched polypropylene (CPP) - based resin material over substantially the entire surface, is provided by being pasted.

[0024] As shown in FIG. 4, the lid body 30 is formed in a "convex" shape having a narrow - width portion 32 and a wide - width portion 34 vertically when viewed in cross - section from the direction along the long - side portion of the bottom wall 22 of the exterior body 20. As shown in FIG. 5, the width along the front - rear direction of the wide - width portion 34 constituting the lower side of the lid body 30 is the same as the interval between the pair of main body walls 24, and the narrow - width portion 32 constituting the upper side of the lid body 30 is formed at the center in the width direction (front - rear direction) of the wide - width portion 34.

[0025] In other words, half the difference between the width of the wide section 34 and the width of the narrow section 32 is the same as the overhang length L of the overhang section 26, and when the lid 30 is installed on the upper end of the outer casing 20 (between the upper ends of the pair of main body walls 24), its narrow section 32 is sandwiched from the front and rear by the overhang section 26 (see Figure 5).

[0026] In other words, the opposing end faces 26A (see Figure 3) of each protruding portion 26 abut against the front-to-back oriented side surface 32A (see Figure 4) of the narrow portion 32, and the protruding portions 26 fit into the stepped portion 36 formed by the narrow portion 32 and the wide portion 34. In this state, the lid 30 is joined to the upper end of the outer casing 20 by welding, thereby sealing the upper end.

[0027] Furthermore, the upper surface (outer surface) of the narrow section 32 and the upper surface (outer surface) of the protruding section 26 are flush with each other (see Figure 5). That is, the thickness (height) H1 of the narrow section 32 is the same as the plate thickness D of the protruding section 26 (exterior body 20) (H1=D). Also, the thickness (height) H2 of the wide section 34 is formed to be thicker than the thickness H1 of the narrow section 32 (H2>H1).

[0028] Furthermore, as shown in Figure 5, the lower surface of the wide portion 34 (the inner surface of the lid 30) is provided with a second heat conductive sheet 38, which is made of a silicone-based resin material and has a predetermined thickness D2 (thinner than the thickness D1 of the heat conductive sheet 28: D1>D2), attached to almost the entire surface.

[0029] In this embodiment, the thickness D1 of the thermal conductive sheet 28 is the sum of the thickness H2 of the wide portion 34 of the lid 30 and the thickness D2 of the thermal conductive sheet 38. Specifically, as an example, H2 = D2 = 1 mm, and D1 = 2 mm. This configuration ensures the strength of the battery 10 while suppressing a reduction in the volumetric energy density of the electrode body 12. Furthermore, the thermal conductivity of the thermal conductive sheet 28 and the thermal conductive sheet 38 is higher than that of the insulating film 27, and is set to 1.5 W / (m·K) or higher.

[0030] The operation (manufacturing method) of the battery 10 according to this embodiment, which has the configuration described above, will now be explained.

[0031] First, as shown in Figure 6(A), a heat conductive sheet 28 is attached to the inner surface of the bottom wall 22 of the outer casing 20, and an insulating film 27 is attached to the inner surface of the main body wall 24. Then, as shown in Figure 6(B), the protruding portions 26 of the outer casing 20 are moved in a direction that separates them from each other to widen the upper end of the outer casing 20 (opening process), and the electrode body 12 is inserted into the widened upper end of the outer casing 20 from above (electrode body insertion process). Figure 6(C) shows the state in which the electrode body 12 has been inserted (housed) in the outer casing 20.

[0032] Next, as shown in Figure 6(D), the lid 30 is inserted into the upper end of the outer casing 20 in which the electrode body 12 is inserted (housed) (lid insertion step). A heat conductive sheet 38 is attached to the lower surface of the wide portion 34 of the lid 30 in advance. Although not shown in the illustration, at this time as well, as shown in Figure 6(B), the protruding portions 26 of the outer casing 20 are moved in a direction that separates them from each other to widen the upper end of the outer casing 20 and insert the lid 30.

[0033] Once the lid 30 is inserted onto the upper end of the outer casing 20 (above the electrode body 12), the protruding portions 26 are moved toward each other, as shown in Figure 6(E), to clamp the narrow portion 32 of the lid 30 with the protruding portions 26, thereby sealing the upper end of the outer casing 20 (sealing process). That is, with the end faces 26A (see Figure 3) of each protruding portion 26 in contact with each side surface 32A (see Figure 4) of the narrow portion 32, the lid 30 is joined (sealed) to the upper end of the outer casing 20 by welding.

[0034] At this time, the terminal portions 14 (see Figures 1 and 2) provided on both the left and right sides of the electrode body 12 are also joined by welding to the left and right edges of the bottom wall 22 and the main body wall 24, and to the left and right ends of the lid 30, so as to seal the opening 18 of the outer casing 20. This results in the production of a battery 10 as shown in Figure 1.

[0035] Here, the plate thickness D of the bottom wall 22 is made thinner than the thickness H2 of the wide part 34 of the lid 30 (H2 > D), and the thickness D1 of the thermal conductive sheet 28 is made thicker than the thickness D2 of the thermal conductive sheet 38 (D1 > D2). Therefore, the heat dissipation of the outer casing 20, especially on the bottom wall 22 side, can be improved, and the battery 10 can be cooled (heat dissipated) efficiently.

[0036] Furthermore, since the main body wall 24 is larger than the bottom wall 22, the reduction in the volumetric energy density of the electrode body 12 can be suppressed compared to the case where the main body wall 24 is smaller than the bottom wall 22. In addition, since an insulating film 27 thinner than the thermal conductive sheet 38 is provided on the inner surface of each main body wall 24, the outer casing 20 and the electrode body 12 can be effectively insulated while suppressing the reduction in the volumetric energy density of the electrode body 12.

[0037] Furthermore, since the insulating film 27 only needs to be attached to the inner surface of each main body wall 24, the amount of insulating film 27 used can be reduced compared to the case where the insulating film 27 is wrapped around the electrode body 12, and the electrode body 12 and the insulating film 27 can be brought into close contact. Therefore, compared to the case where the insulating film 27 is wrapped around the electrode body 12, that is, when a gap (air gap) is formed between the electrode body 12 and the insulating film 27, heat dissipation can be improved, and the battery 10 can be cooled (heat dissipated) efficiently.

[0038] Furthermore, the upper surface of the narrow portion 32 of the lid 30 and the upper surface of the protruding portion 26 of the outer casing 20 are flush. Therefore, compared to, for example, a case where the upper surface of the protruding portion 26 protrudes upward from the upper surface of the narrow portion 32, it becomes easier to bring a cooling member (not shown) into contact with the lid 30 to cool (dissipate heat from) the battery 10. Thus, the battery 10 can be cooled efficiently.

[0039] Furthermore, since this battery 10 is configured to hold the electrode body 12 between a heat conductive sheet 28 provided on the inner surface of the bottom wall 22 of the outer casing 20 and a heat conductive sheet 38 provided on the lower surface of the wide portion 34 of the lid 30, the electrode body 12 can be effectively fixed in close contact with the outer casing 20.

[0040] Furthermore, in the lid 30, the thickness H2 of the wide portion 34 is formed to be thicker than the thickness H1 of the narrow portion 32 (H2 > H1). Therefore, even if the plate thickness D of the outer casing 20 (especially the protruding portion 26) is thin, it is possible to prevent damage to the electrode body 12 when welding the lid 30 to the outer casing 20.

[0041] Furthermore, the electrode body 12 has a terminal portion 14 that can close the opening 18 of the outer casing 20. In other words, the attachment of the terminal portion 14 to the electrode body 12 by welding can be performed before the electrode body 12 is inserted into the outer casing 20. Therefore, compared to the case where the terminal portion 14 is welded to the electrode body 12 after the electrode body 12 has been inserted into the outer casing 20, the generation of foreign matter and fumes can be suppressed.

[0042] Furthermore, since the electrode body 12 has a terminal portion 14 that can close the opening 18 of the outer casing 20, the opening 18 can be closed simply by inserting the electrode body 12 into the outer casing 20. In other words, since the cover 30 is also welded and joined to the terminal portion 14, it becomes easier to position and assemble the cover 30 relative to the outer casing 20, thereby improving the ease of assembly between the outer casing 20 and the cover 30.

[0043] The battery 10 according to this embodiment has been described above based on the drawings. However, the battery 10 according to this embodiment is not limited to the illustrated version, and can be modified as appropriate without departing from the spirit of the present invention. For example, the length in the left-right direction, the length in the up-down direction (height), and the length in the front-back direction (thickness) of the battery 10 are not limited to the lengths shown.

[0044] Furthermore, the width (length) of the narrow portion 32 of the lid 30 along the front-rear direction and the overhang length L of the protruding portion 26 of the outer casing 20 are exaggerated in each figure and are not limited to the lengths shown. Therefore, for example, the width (length) of the narrow portion 32 along the front-rear direction may be twice or more the width (length) of the overhang length L of the protruding portion 26. [Explanation of Symbols]

[0045] 10 batteries 12 Electrode body 14 Terminal section 18 Opening 20 Exterior 22 Bottom wall 24 Main wall 27 Insulating film 28. Thermal conductive sheet (first thermal conductive material) 30 Lid 38. Thermal conductive sheet (second thermal conductive material)

Claims

1. An exterior body having a rectangular, flat bottom wall and a pair of main walls integrally erected on the long sides of the bottom wall, The electrode body housed in the aforementioned outer casing, A cover is provided between the ends of the pair of main body walls opposite to the bottom wall, The first heat conductive material provided on the inner surface of the bottom wall, A second heat conductive material provided on the inner surface of the lid, Equipped with, The thickness of the bottom wall is thinner than the thickness of the lid. A battery in which the thickness of the first thermal conductive material is greater than the thickness of the second thermal conductive material.

2. The battery according to claim 1, wherein an insulating film thinner than the second thermal conductive material is provided on the inner surface of the main body wall.

3. The battery according to claim 1 or claim 2, wherein the main body wall is larger than the bottom wall.

4. The battery according to claim 1 or claim 2, wherein the electrode body has a terminal portion capable of closing the opening of the outer casing on the short side of the bottom wall.

5. The exterior body has protruding portions at the ends of the pair of main body walls opposite to the bottom wall, each protruding in a direction that moves toward each other. The lid is formed in a "convex" shape having a narrow portion and a wide portion when viewed in cross-section from a direction along the long side of the bottom wall. The battery according to claim 1 or claim 2, wherein the narrow portion is sandwiched between the protruding portion, and the outer surface of the narrow portion and the outer surface of the protruding portion are flush.

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