Battery

Abstract

The utility model relates to a battery which is provided with an outer packaging body, an electrode body is accommodated in the outer packaging body, the overlapped peripheral part of the outer packaging body is jointed and bent through hot melting, and the peripheral part is in the following bent shape: the top end part of the peripheral part is bent by 180 degrees towards one direction and then is bent by 180 degrees towards the direction opposite to the direction, and the top end part of the peripheral part is bent by 180 degrees towards the direction opposite to the direction opposite to the direction opposite to the direction opposite to the direction opposite to the direction opposite to the direction opposite to the direction opposite to the direction opposite to the direction. And then bending for 90 degrees towards the opposite direction. As a result, the tip of the peripheral edge of the exterior body, i.e., the initial bent portion, can have a long bending length.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of batteries. BACKGROUND

[0002] In the prior art, a battery manufacturing method is known in which a peripheral edge portion of a heat-sealed outer body, i.e., a laminated film, of a laminated battery is bent (see, for example, Patent Literature 1).

[0003] Patent Literature 1: Japanese Patent Application Publication No. 2023-148454.

[0004] When the peripheral edge portion of the laminated film (outer body) that is heat-sealed is bent in one direction, the initial bending portion as the tip end portion thereof cannot adopt a long bending length in consideration of the amount of subsequent bending (the amount of rolling inward). That is, if the initial bending portion adopts a long bending length, the peripheral edge portion that is finally bent can possibly protrude outward in the thickness direction of the battery main body, and if it is bent in a manner not to protrude outward in the thickness direction of the battery main body, the portion that is bent first can possibly be deformed.

[0005] However, from the viewpoint of reducing the gas permeability in the battery main body, it is desirable that the initial bending portion adopt a long bending length. In this regard, there is room for improvement in the configuration in which the initial bending portion of the peripheral edge portion is made to adopt a long bending length even in the limited space that does not protrude outward in the thickness direction of the battery main body to reduce the gas permeability. SUMMARY

[0006] In view of the above, the utility model wants to solve the technical problem of how to obtain a battery in which the tip end portion of the peripheral edge portion of the outer body, i.e., the initial bending portion, can adopt a long bending length.

[0007] To solve the above technical problem, the first aspect of the utility model relates to a battery having an outer body in which an electrode body is accommodated, and a peripheral edge portion of the outer body is joined by heat sealing and bent, the peripheral edge portion being bent in the following manner: the tip end portion thereof is bent 180 degrees in one direction, bent 180 degrees in the opposite direction of the one direction, and then bent 90 degrees in the opposite direction.

[0008] According to the battery of the first aspect, the overlapping peripheral edge portion of the exterior body in which the electrode body is housed is joined by heat welding and is bent. The peripheral edge portion is bent 180 degrees in one direction at the top end portion thereof, is bent 180 degrees in the opposite direction to the one direction, and is further bent 90 degrees in the opposite direction to the one direction. That is, the initial bent portion of the top end portion of the peripheral edge portion of the exterior body is not constituted by being rolled in the inside. Therefore, the bending length of the initial bent portion of the top end portion of the peripheral edge portion of the exterior body can take a longer value. In addition, in the "180 degrees" and "90 degrees" in the present application, "approximately 180 degrees" and "approximately 90 degrees" are also included.

[0009] In addition, the second aspect of the present application is a battery in which, in the battery of the first aspect, the exterior body forms a housing portion in which the electrode body is housed, and the bent peripheral edge portion does not protrude to the outside in the thickness direction of the housing portion.

[0010] According to the battery of the second aspect, the peripheral edge portion does not protrude to the outside in the thickness direction of the housing portion in which the electrode body is housed. Therefore, when a plurality of batteries are arranged in the thickness direction, the arrangement can be performed with high accuracy.

[0011] As described above, according to the present application, the top end portion of the peripheral edge portion of the exterior body, that is, the initial bent portion can have a longer bending length. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a side view schematic diagram showing a state in which the peripheral edge portion of the laminated film of the battery of the present embodiment is welded.

[0013] Figure 2A is a side view schematic diagram showing a state in which the top end portion of the peripheral edge portion of the laminated film of the battery according to the present embodiment is bent 180 degrees in one direction. Figure 2B is a side view schematic diagram showing a state in which the top end portion of the bent peripheral edge portion of Figure 2A is bent 180 degrees in the opposite direction to the one direction. Figure 2C is a side view schematic diagram showing a state in which the top end portion of the bent peripheral edge portion of Figure 2B is further bent 90 degrees in the opposite direction to the one direction.

[0014] Figure 3A is a side view schematic diagram showing a state in which the bent peripheral edge portion of the laminated film of the battery according to the comparative example protrudes from the main body of the battery. Figure 3B is a side view schematic diagram showing a state in which the peripheral edge portion of the laminated film of the battery according to the comparative example is deformed and bent. DETAILED DESCRIPTION

[0015] Embodiments of the present application will be described in detail below with reference to the drawings. Note that the size, the relative position, and the like of a component in each drawing are not necessarily to scale and can be illustrated differently from the actual ones. In addition, the term "step" in this embodiment does not always refer to a single independent step, but also includes a case where a process is performed several times or a case where a process is performed in combination with another step.

[0016] In addition, as an example, the battery 10 related to this embodiment is a battery cell housed inside a battery pack (not shown) mounted under the floor of a battery electric vehicle (BEV: Battery Electric Vehicle).

[0017] The battery pack is composed of a plurality of battery modules (not shown) electrically connected to each other. A plurality of the battery 10 as a battery cell is arranged in the thickness direction inside each battery module, and a buffer material (not shown) as a thin plate-shaped member capable of elastic deformation is arranged between adjacent battery 10, for example, in the thickness direction of the battery 10.

[0018] In Figure 1 , Figure 2A , Figure 2B , Figure 2C A part of the battery 10 is schematically shown in Figure 1 , Figure 2A , Figure 2B , Figure 2C As shown in

[0019] As the electrode, for example, an electrode in which a layer containing an electrode active material is formed on one or both surfaces of a current collector is used. As the separator, for example, a microporous film composed of a resin such as polyethylene is used. The laminate film 12 is a laminate having a metal layer containing a metal such as aluminum and a heat-seal layer.

[0020] In this embodiment, as an example, the housing portion 16 of the electrode body as a battery main body is formed by folding and attaching the sheet-shaped laminate film 12 after embossing. In addition, the laminate film 12 can adopt either a single cup embossing structure in which embossing is performed at one place or a double cup embossing structure in which embossing is performed at two places.

[0021] Next, a manufacturing method of the battery 10 (battery cell) configured as described above will be described. In addition, "180 degrees" and "90 degrees" in this embodiment also include "approximately 180 degrees" and "approximately 90 degrees".

[0022] The battery 10 manufactured by the manufacturing method of the present embodiment is a so-called laminate type battery that uses the laminate film 12 as an exterior body. First, as shown in Figure 1 the peripheral edge portions 14 of the laminate film 12, which has an electrode body not shown housed therein and is folded into two portions, are overlapped with each other. Then, the inner surfaces of the mutually overlapped peripheral edge portions 14, which are heat seal layers, are joined by heat fusion (joining step).

[0023] Next, as shown in Figure 2A , Figure 2B , Figure 2C the peripheral edge portions 14 are bent toward the housing portions 16 (bending step). Specifically, as shown in Figure 2A the tip end portions of the peripheral edge portions 14, i.e., the first bent portions 14A, are bent 180 degrees toward the lower side (one direction) shown in the drawing. Next, as shown in Figure 2B the next bent portions 14B of the peripheral edge portions 14 are bent 180 degrees toward the upper side (the direction opposite to the one direction) shown in the drawing.

[0024] Then, as shown in Figure 2C the last bent portions 14C of the peripheral edge portions 14 are further bent 90 degrees toward the upper side (the direction opposite to the one direction) shown in the drawing. In addition, the peripheral edge portions 14 bent in this bending step are bent in such a manner that they do not protrude toward the outside in the thickness direction of the housing portions 16 in which the electrode bodies are housed.

[0025] In addition, when the length of the first bent portions 14A of the peripheral edge portions 14 is La, the length of the next bent portions 14B is Lb, and the length of the last bent portions 14C is Lc, if, for example, as shown in Figure 3A , Figure 3B all are bent in the order of 180 degrees, 180 degrees, and 90 degrees toward the lower side (one direction), the relationship Lc > Lb > La is obtained. However, in the present embodiment, the bending is performed as described above, and thus the relationship Lc > Lb = La can be obtained. Therefore, the length La of the first bent portions 14A, which are the tip end portions of the peripheral edge portions 14, can take a longer value.

[0026] Next, the effects of the battery 10 of the present embodiment and the manufacturing method thereof having the above-described configuration will be described.

[0027] First, the battery 100 involved in the comparative example shown in Figure 3A , Figure 3B will be described. As shown in Figure 3A , Figure 3BAs shown, the peripheral portion 114 of the laminated film 112 of the battery 100 is bent 180 degrees downward (in one direction) as the initial bending portion 114A, which is the top portion. The next bending portion 114B is also bent 180 degrees downward (in one direction) as shown. Furthermore, the final bending portion 114C is also bent 90 degrees downward (in one direction) as shown.

[0028] Here, as Figure 3A As shown, if the bending length of the initial bend 114A is taken to be a longer value, the final bend peripheral portion 114 protrudes outward in the thickness direction of the receiving portion 116. Furthermore, in this state, to prevent the bend peripheral portion 114 from protruding outward in the thickness direction of the receiving portion 116, for example, when it is pushed upward as shown in the figure, as... Figure 3B As shown, the deformation occurs between the initial bend 114A and the next bend 114B.

[0029] In contrast, in the battery 10 according to this embodiment, such as Figure 2A , Figure 2B , Figure 2C As shown, the top part of the periphery 14 of the laminated film 12, i.e. the initial bent part 14A, is bent 180 degrees downward (in one direction) as shown in the figure. Then, the next bent part 14B is bent 180 degrees upward (in the opposite direction) as shown in the figure. Furthermore, the last bent part 14C is also bent 90 degrees upward (in the opposite direction) as shown in the figure.

[0030] That is, in the battery 10 according to this embodiment, the top end of the peripheral portion 14 of the laminated film 12, i.e., the initial bent portion 14A, is not rolled inward. Therefore, even if the bending length of the initial bent portion 14A is taken to be a long value, the bent peripheral portion 14 will not deform, and the initial bent portion 14A can adopt a long bending length. Therefore, the gas permeability in the housing portion 16 can be reduced.

[0031] Furthermore, during the bending process, the peripheral portion 14 is bent in a manner that does not protrude outward in the thickness direction of the receiving portion 16. In other words, the bent peripheral portion 14 does not protrude outward in the thickness direction of the receiving portion 16. Therefore, when multiple batteries 10 are arranged and received in the thickness direction, each battery 10 can be arranged and received with high precision.

[0032] Thus, according to the battery 10 of this embodiment, even in the limited space where the bent peripheral portion 14 does not protrude outward in the thickness direction of the receiving portion 16, the initial bent portion 14A of the peripheral portion 14 can be made to have a longer bending length, which can help reduce the gas permeability in the receiving portion 16.

[0033] The battery 10 and the manufacturing method thereof according to the present embodiment have been described above with reference to the drawings, but the battery 10 and the manufacturing method thereof according to the present embodiment are not limited to the illustrated content, and design changes can be appropriately made within a range not departing from the gist of the present application. For example, in the above-described embodiment, the lower side of the drawing is taken as one direction, but the upper side of the drawing can also be taken as one direction.

[0034] In addition, the kind and size of the electrode body, and the number of electrodes and separators included in the electrode body are not particularly limited, and can be selected according to the scale and use of the battery 10. In addition, the vehicle is not limited to an electric vehicle, and can also be a hybrid vehicle (HV: Hybrid Vehicle) or a plug-in hybrid electric vehicle (PHEV: Plug-in Hybrid Electric Vehicle) equipped with an engine.

Claims

1. A battery characterized by comprising: an outer body, an inside of which houses an electrode body, overlapping peripheral edge portions of the outer body being joined by heat fusion and being bent, the peripheral edge portions being bent in a shape in which a tip end portion thereof is bent 180 degrees in one direction, bent 180 degrees in an opposite direction of the one direction, and bent 90 degrees in the opposite direction.

2. The battery of claim 1, wherein, the outer body forming a housing portion, the electrode body being housed inside the housing portion, the bent peripheral edge portions not protruding to an outside in a thickness direction of the housing portion.

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