Battery cell

Abstract

A battery cell has a battery main body, an accommodating member that accommodates the battery main body, and a resin member. The accommodating member has a first film portion that covers a first surface of the battery main body and a second film portion that covers a second surface on the opposite side of the first surface. A welding portion that protrudes from the side surface and welds the inner side surface of the first film portion and the inner side surface of the second film portion is provided on the side surface of the accommodating member. The resin member covers the side surface of the accommodating member and the welding portion.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a battery cell. Background Technology

[0002] The battery cell disclosed in Japanese Patent Application Publication No. 2020-004712 includes a battery body and a housing component. The battery body is housed within the housing component. The housing component has a first film portion covering one surface of the battery body and a second film portion covering the other surface of the battery body. A weld portion is provided on the side of the housing component for welding the inner surfaces of the first film portion and the inner surfaces of the second film portion together. Summary of the Invention

[0003] If the sealing performance of the welded joint is reduced, gases and liquids can easily move between the inside and outside of the housing component through the welded joint, thereby reducing the quality of the battery cell. This specification proposes a technique for achieving high sealing performance in the welded joint.

[0004] The battery cell according to the first aspect of the present invention has:

[0005] Battery body;

[0006] A housing component that houses the battery body; and

[0007] Resin components.

[0008] The receiving component has:

[0009] A first membrane portion, which covers a first surface of the battery body; and

[0010] The second membrane covers the second surface on the side opposite to the first surface.

[0011] A weld portion is provided on the side of the receiving component, which protrudes from the side and welds the inner surface of the first membrane portion and the inner surface of the second membrane portion together.

[0012] The resin component covers the side surface of the receiving component and the welded portion.

[0013] In the aforementioned battery cell, the resin component covers the sides of the housing component and the welded portion. Therefore, high sealing performance can be achieved at the welded portion.

[0014] In the battery cell according to the first aspect of the present invention,

[0015] When viewed from above along the thickness direction of the battery cell, the side of the receiving component has a first side and a second side extending in a direction intersecting the first side.

[0016] The welding portion has a first welding portion disposed on the first side and a second welding portion disposed on the second side.

[0017] The resin component covers the first side, the first weld, the second side, and the second weld.

[0018] According to the above-mentioned battery cell, since the resin component covers the first side and the second side, the rigidity of the battery cell can be improved.

[0019] In the battery cell according to the first aspect of the present invention,

[0020] The length of the battery body is more than 5 times the width of the battery body.

[0021] In the battery cell according to the first aspect of the present invention,

[0022] It also has a heat-conducting component that covers the surface of the resin component and has a higher thermal conductivity than the resin component.

[0023] According to the aforementioned battery cell, the heat generated in the battery body can be easily released to the outside.

[0024] In the battery cell according to the first aspect of the present invention,

[0025] It has a sealing material disposed between the resin component and the welded part.

[0026] Based on the aforementioned battery cell, higher sealing performance can be achieved at the welding section. Attached Figure Description

[0027] Hereinafter, with reference to the accompanying drawings, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described, in which the same reference numerals denote the same elements, and wherein:

[0028] Figure 1 This is a perspective view of the battery cell of Example 1.

[0029] Figure 2 This is a top view of the battery cell in Example 1.

[0030] Figure 3 It is a cross-sectional view of the battery cell before the housing components are sealed.

[0031] Figure 4 This is a top view of the battery cell after the housing components are sealed and before the resin components are installed.

[0032] Figure 5 yes Figure 2 VV sectional view;

[0033] Figure 6 This is a cross-sectional view of the battery cell in Example 2 (and...). Figure 5 (Corresponding sectional view).

[0034] Figure 7 This is a cross-sectional view of the battery cell in Example 3 (and...). Figure 5 (Corresponding sectional view). Detailed Implementation

[0035] Example 1

[0036] Figure 1 The battery cell 100 shown is used, for example, in an electrified vehicle. The battery cell 100 has a generally rectangular plate shape. Hereinafter, the thickness direction of the battery cell 100 will be referred to as the z-direction, the length direction as the x-direction, and the width direction (i.e., the direction orthogonal to the z and x directions) as the y-direction. When using the battery cell 100, multiple battery cells 100 are stacked in the z-direction to form a battery module. Figure 1 As shown, the battery cell 100 has a housing component 20. (As indicated...) Figure 2 As shown, a battery body 10 is housed inside the housing component 20. The housing component 20 houses the battery body 10 and the electrolyte. An electrode plate 50 is provided at one end of the battery cell 100 in the x-direction, and an electrode plate 52 is provided at the other end of the battery cell 100 in the x-direction. Electrode plate 50 is the positive electrode, and electrode plate 52 is the negative electrode. Furthermore, the battery cell 100 has a resin component 60 covering the sides of the housing component 20.

[0037] The battery body 10 is a battery capable of repeated charging and discharging. For example... Figure 2 As shown, the battery body 10 has a generally plate-like shape. The ratio of the length L to the width W of the battery body 10 (more specifically, the value obtained by dividing the length L by the width W) is called the aspect ratio. In this embodiment, the aspect ratio of the battery body 10 is 5 or more. The aspect ratio of the battery body 10 can be 10 or more. Because the aspect ratio of the battery body 10 is high, the housing member 20 has side surfaces 20a and 20c extending along the short side direction and side surfaces 20b and 20d extending along the long side direction. The battery body 10 is a stack of multiple positive electrode current collector foils and negative electrode current collector foils alternately arranged in the z-direction via a separator. Although not shown, a positive electrode current collector foil portion formed by gathering the positive electrode current collector foils is provided at one end of the battery body 10 in the x-direction. An electrode plate 50 is connected to the positive electrode current collector foil portion. And, although not shown, a negative electrode current collector foil portion formed by gathering the negative electrode current collector foils is provided at the other end of the battery body 10 in the x-direction. An electrode plate 52 is connected to the negative electrode current collector foil portion. The battery body 10 is immersed in an electrolyte that fills the interior of the housing component 20.

[0038] Figure 3 This is a cross-sectional view of the battery cell 100 before the housing component 20 is sealed. (See image.) Figure 3 As shown, the receiving member 20 is composed of a film. For example, a laminated film with resin coatings on both surfaces of an aluminum film can be used as the film constituting the receiving member 20. The film constituting the receiving member 20 is molded into a container shape having a first film portion 22 and a second film portion 32. A crease 21 is provided on the side 20d of the receiving member 20. The second film portion 32 is capable of swinging relative to the first film portion 22 about the crease 21.

[0039] The first membrane portion 22 has a receiving portion 24 and a frame portion 26. The receiving portion 24 is cup-shaped with a recess for receiving the battery body 10. The frame portion 26 is disposed around the receiving portion 24 and extends toward the side opposite to the receiving portion 24. The second membrane portion 32 has a receiving portion 34 and a frame portion 36. The receiving portion 34 is cup-shaped with a recess for receiving the battery body 10. The frame portion 36 is disposed around the receiving portion 34 and extends toward the side opposite to the receiving portion 34. When the receiving member 20 is closed, the receiving portion 34 covers the upper surface 10a of the battery body 10. And, when the receiving member 20 is closed, the frame portion 36 overlaps the frame portion 26. In the portion where the frame portion 36 overlaps with the frame portion 26, the lower surface of the frame portion 36 (i.e., the surface that becomes the inner side of the receiving member 20) and the upper surface of the frame portion 26 (i.e., the surface that becomes the inner side of the receiving member 20) are welded together. Hereinafter, the portion where frame portion 36 overlaps with frame portion 26 will be referred to as weld portion 40. In weld portion 40, the receiving component 20 is sealed. The width of weld portion 40 is, for example, 1 mm.

[0040] Figure 4 This is a top view of the battery cell 100 after the housing component 20 has been sealed and before the resin component 60 has been installed. (See attached image.) Figure 4 As shown, the welding portion 40 is provided on the sides 20a to 20c of the receiving member 20, excluding the side 20d. That is, the welding portion 40 is provided on sides 20a, 20b, and 20c, but not on side 20d. The welding portion 40 protrudes from sides 20a, 20b, and 20c. Hereinafter, the portion of the welding portion 40 provided on side 20a will be referred to as welding portion 40a, the portion provided on side 20b will be referred to as welding portion 40b, and the portion provided on side 20c will be referred to as welding portion 40c.

[0041] like Figure 1 , 2As shown, electrode plates 50 and 52 extend from the battery body 10 to the outer side of the receiving member 20. In welding section 40a, electrode plate 50 extends from the inner side of the receiving member 20 to the outer side through frame portion 26 and frame portion 36. In welding section 40c, electrode plate 52 extends from the inner side of the receiving member 20 to the outer side through frame portion 26 and frame portion 36. In the area of ​​welding section 40 where electrode plates 50 and 52 are not present, frame portion 36 is welded to frame portion 26. In the area of ​​welding section 40a where electrode plate 50 is present, frame portion 26 is welded to the lower surface of electrode plate 50, and frame portion 36 is welded to the upper surface of electrode plate 50. In the area of ​​welding section 40c where electrode plate 52 is present, frame portion 26 is welded to the lower surface of electrode plate 52, and frame portion 36 is welded to the upper surface of electrode plate 52.

[0042] like Figure 1 , 2 As shown, the battery cell 100 has a resin component 60. The resin component 60 covers the welded portion 40. More specifically, the resin component 60 covers the welded portions 40a, 40b, and 40c entirely. Therefore, as Figure 5 As shown, the resin component 60 covers the entire outer peripheral end 38 of the interface between the frame portion 26 and the frame portion 36. Furthermore, the resin component 60 covers the side surfaces 20a to 20c. The resin component 60 is formed by injection molding and is tightly fitted and fixed to the receiving component 20. The thickness of the resin component 60 (i.e., the dimension in the z-direction) is approximately equal to the thickness of the battery body 10. However, the thickness of the resin component 60 (i.e., the dimension in the z-direction) may be thinner than the thickness of the battery body 10.

[0043] In the above embodiment, the resin component 60 covers the weld portion 40 of the receiving component 20. Therefore, high sealing performance can be achieved at the weld portion 40. In particular, the resin component 60 covers the weld portion 40 and the sides 20a to 20c of the receiving component 20, thus achieving even higher sealing performance. Therefore, even if the width of the weld portion 40 is set to be shorter than before, high sealing performance can still be achieved.

[0044] Furthermore, in the above embodiments, the resin component 60 is disposed around the receiving component 20, thus the battery cell 100 has high rigidity.

[0045] In the above embodiment, the resin component 60 extends along the xy plane. Therefore, when using the battery cell 100, it is easy to stack multiple battery cells 100, thereby improving the assemblability of the battery cell 100.

[0046] Example 2

[0047] The battery cell 102 in Example 2 differs from that in Example 1 in that it has a heat-conducting component 62. Regarding other structures, Example 2 is the same as Example 1.

[0048] The heat-conducting component 62 covers the surface of the resin component 60. The heat-conducting component 62 may cover the entire surface of the resin component 60 or only a portion of its surface. The heat-conducting component 62 has a higher thermal conductivity than the resin component 60. The heat-conducting component 62 is, for example, an aluminum sheet.

[0049] During the charging and discharging of the battery cell, heat is generated in the battery body. The battery cell 102 of Embodiment 2 has a heat-conducting component 62 covering the surface of the resin component 60. The heat-conducting component 62 has a higher thermal conductivity than the resin component 60. Therefore, the heat generated in the battery body 10 is effectively released to the outside via the heat-conducting component 62. Thus, the temperature rise of the battery cell 102 can be suppressed.

[0050] Example 3

[0051] The difference between the battery cell 103 in Example 3 and that in Example 1 is that it has a sealing material 64. Regarding other structures, Example 3 is the same as Example 1.

[0052] A sealing material 64 is disposed between the resin component 60 and the welded portion 40. The sealing material 64 covers the outer peripheral end 38 of the interface between the frame portion 26 of the first membrane portion 22 and the frame portion 36 of the second membrane portion 32. Therefore, liquid is difficult to pass through the interface between the frame portion 26 and the frame portion 36, thereby preventing liquid from entering the battery cell 100 from the outside.

[0053] In embodiments 1 to 3, uneven portions may be provided on the upper and lower surfaces of the resin component 60. According to this structure, when multiple battery cells are stacked, the uneven portions function as positioning components for adjacent battery cells. Therefore, the assemblability of the battery cells is improved.

[0054] The resin component 60 covers sides 20a to 20c. However, the resin component 60 may cover only at least one of the sides 20a to 20c. For example, the resin component 60 may be provided on the welded portion 40b and the side 20b, but not on the welded portions 40a and 40c and the sides 20a and 20c.

[0055] The lower surface 10b is an example of the "first surface". The upper surface 10a is an example of the "second surface".

[0056] The embodiments have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations to the specific examples illustrated above. The technical elements described in this specification or drawings achieve technical utility through individual or various combinations, and are not limited to the combinations described in the technical solution at the time of application. Furthermore, the technology illustrated in this specification or drawings simultaneously achieves multiple objectives, and achieving one of these objectives is itself technically practical.

Claims

1. A battery cell, characterized in that, have: Battery body; A housing component that houses the battery body; and Resin components, The receiving component has: A first membrane portion, which covers a first surface of the battery body; and The second membrane portion covers the second surface on the side opposite to the first surface. A weld portion is provided on the side of the receiving component, protruding from the side and welding the inner surface of the first membrane portion and the inner surface of the second membrane portion together. The resin component covers the side surface of the receiving component and the welded portion.

2. The battery cell according to claim 1, characterized in that, When viewed from above along the thickness direction of the battery cell, the side of the receiving component has a first side and a second side extending in a direction intersecting the first side. The welding portion has a first welding portion disposed on the first side and a second welding portion disposed on the second side. The resin component covers the first side, the first weld, the second side, and the second weld.

3. The battery cell according to claim 1 or 2, characterized in that, The length of the battery body is more than 5 times the width of the battery body.

4. The battery cell according to claim 1 or 2, characterized in that, It also has a heat-conducting component that covers the surface of the resin component and has a higher thermal conductivity than the resin component.

5. The battery cell according to claim 1 or 2, characterized in that, It has a sealing material disposed between the resin component and the welded part.

Images