Battery case and method for manufacturing the same, and battery

Abstract

The application relates to the technical field of batteries, and discloses a battery shell, a preparation method thereof and a battery. The battery shell comprises a lower shell and an upper cover, the lower shell is integrally formed from a plate material, the plate material comprises a metal plate and an insulating layer located on the inner side surface of the metal plate; the opening edge of the lower shell is provided with a flange, the flange is a folding structure formed by bending the plate material, the outer folding layer of the flange is the metal plate, and the inner folding layer is the insulating layer; and the upper cover is welded with the metal plate of the outer folding layer of the flange. According to the battery shell disclosed by the application, the insulating layer is arranged on the inner side surface of the metal plate before the metal plate is used to integrally form the lower shell of the battery, the metal plate and the insulating layer can be completely attached, so that the quality of the finally formed lower shell is improved; a circle of plate material of the opening edge of the lower shell is bent to form the flange, the design can improve the connecting strength and sealing effect of the lower shell and the upper cover; in addition, the design of the flange is simpler than the processing mode of cutting the insulating layer, and is convenient for industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to battery technology, in particular to a battery shell and a preparation method thereof, and a battery. BACKGROUND

[0002] In order to improve the safety performance of the battery, an insulating layer is generally arranged on the inner surface of the lower shell of the battery. In the prior art, if the metal plate is first stamped into shape and then the insulating layer is arranged on the inner surface of the metal plate, the insulating layer cannot completely adhere to the inner surface of the metal plate. If the insulating layer is arranged on the inner surface of the metal plate first and then the lower shell is formed by stamping, after the lower shell is formed, the insulating layer needs to be cut at the welding position of the lower shell and the upper cover. However, such processing is complex and is not conducive to industrial production. SUMMARY

[0003] The present application discloses a battery shell and a preparation method thereof, and a battery, which are used to simplify the preparation process of the battery shell and improve the preparation yield of the battery shell.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0005] In a first aspect, a battery shell includes a lower shell and an upper cover. The lower shell is integrally formed from a plate material. The plate material includes a metal plate and an insulating layer on the inner side surface of the metal plate. The opening edge of the lower shell is provided with a flange. The flange is a folding structure formed by bending the plate material. The folding outer layer of the flange is the metal plate, and the folding inner layer is the insulating layer. The upper cover is welded with the metal plate of the folding outer layer of the flange.

[0006] In a second aspect, a preparation method of a battery shell includes the following steps:

[0007] An insulating layer is arranged on one side surface of a metal plate.

[0008] The metal plate provided with the insulating layer is stamped into shape to form the shape of the shell. The opening of the shell has a folding edge. The insulating layer is located on the inner side of the shell.

[0009] The folding edge is bent to form a flange with a folding structure. The folding outer layer of the flange is the metal plate, and the folding inner layer is the insulating layer.

[0010] An upper cover is welded with the metal plate of the folding outer layer of the flange.

[0011] In a third aspect, a battery includes the battery shell according to any one of the above aspects.

[0012] Specifically, in the technical scheme provided by the application, an insulating layer is arranged on the inner side surface of the metal plate before the lower shell of the formed battery is prepared from the metal plate. Thus, the insulating layer can completely adhere to the inner side surface of the metal plate, and the metal plate and the insulating layer constitute a plate material, and the lower shell is integrally formed from the plate material. Therefore, the quality of the finally prepared lower shell can be improved. In addition, the plate material around the opening edge of the lower shell is bent to form a flange. The flange is a folded structure with an inner layer of the insulating layer and an outer layer of the metal plate. The insulating layer is covered by the metal plate. Thus, the upper cover can be directly welded with the metal plate of the folded outer layer of the flange, and the welding surface is large. Therefore, the connection strength and sealing effect of the lower shell and the upper cover can be improved. In addition, the flange of the application is designed by directly bending the edge of the lower shell. Compared with the processing mode of cutting the insulating layer at the edge of the lower shell, the preparation mode of the flange of the application is simpler and is convenient for industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 A schematic diagram of the overall structure of a battery shell is provided for the embodiments of the application.

[0014] Figure 2 A schematic diagram of the partial structure of a battery shell is provided for the embodiments of the application.

[0015] Figure 3 A schematic diagram of the preparation process of a battery shell is provided for the embodiments of the application.

[0016] Figure 4 A flowchart of the preparation method of a battery shell is provided for the embodiments of the application.

[0017] Reference signs:

[0018] 1 - lower shell; 11 - insulating layer; 12 - metal plate; 2 - upper cover

[0019] 3 - shell; 31 - folded edge; 4 - flange; 40 - laminated layer DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0021] As Figure 1 and Figure 2As shown, the battery shell provided by the embodiment of the present application comprises a lower shell 1 and an upper cover 2, the lower shell 1 is integrally formed by a plate material, the plate material comprises a metal plate 12 and an insulating layer 11 located on the inner side surface of the metal plate 12, the inner side surface refers to the surface of the metal plate 12 towards the inside of the lower shell 1, i.e. the surface close to the battery cell; the opening edge of the lower shell 1 is provided with a flange 4, the flange 4 is a folding structure formed by bending the plate material, the outer folding layer of the flange 4 is the metal plate 12, and the inner folding layer is the insulating layer 11; the upper cover 2 is welded with the metal plate 12 of the outer folding layer of the flange 4.

[0022] Specifically, in the technical scheme provided by the present application, the insulating layer 11 is arranged on the inner side surface of the metal plate 12 before the metal plate 12 is used to form the lower shell 1 of the battery, so that the insulating layer 11 can completely adhere to the inner side surface of the metal plate 12, the metal plate 12 and the insulating layer 11 constitute the plate material, and the lower shell 1 is integrally formed by the plate material, thereby improving the quality of the finally formed lower shell 1. In addition, a circle of the plate material at the opening edge of the lower shell 1 is bent to form the flange 4, the flange 4 is a folding structure with the inner layer being the insulating layer 11 and the outer layer being the metal plate 12, and the insulating layer 11 is covered by the metal plate 12, so that the upper cover 2 can be directly welded with the metal plate 12 of the outer folding layer of the flange 4, the welding surface is large, and the connection strength and sealing effect of the lower shell 1 and the upper cover 2 can be improved. In addition, the flange 4 of the present application is designed to be directly formed by bending the edge of the lower shell 1, which is simpler than the processing mode of cutting the insulating layer 11 at the edge of the lower shell 1, and is convenient for industrial production.

[0023] Specifically, the 'outer folding layer is the metal plate, and the inner folding layer is the insulating layer' means that in the folding structure, the outermost of the two layers at both ends is the metal plate, and the insulating layer is sandwiched between the two metal plates.

[0024] In some embodiments, as shown in Figure 1 and Figure 2 , the layers 40 of the flange 4 are parallel to the plane where the opening of the lower shell 1 is located; the upper cover 2 is welded with the top layer 40 of the flange 4.

[0025] Specifically, as shown in Figure 1 , the upper cover 2 covers the opening of the lower shell 1, and the layers 40 of the flange 4 are parallel to the plane where the opening of the lower shell 1 is located, i.e. the metal plate 12 outside the layers 40 is parallel to the plane where the opening is located, and the contact area between the outer metal plate 12 and the upper cover 2 is large, which can increase the welding area between the metal plate 12 and the upper cover 2, thereby strengthening the welding strength of the two.

[0026] In some embodiments, the flange 4 includes an even number of the laminations 40. After the even number of the laminations 40 are formed by folding, the outer sides of the uppermost and lowermost two laminations 40 in the folded structure are the metal plates 12, i.e., the surface of the flange 4 in contact with the upper cover 2 is a metal surface.

[0027] For example, the flange 4 can include two laminations 40, and both of the laminations 40 are parallel to the plane in which the opening is located. Each lamination 40 includes a two-layer structure of a metal plate 12 and an insulating layer 11, as shown in Figure 1 and Figure 2 The flange 4 is a double-lamination 40 structure formed by bending a ring of the plate material of the opening edge of the lower housing 1 to one side of the insulating layer 11. The insulating layer 11 is sandwiched between the metal plates 12, the insulating layer 11 inside the double-lamination 40 structure is referred to as a folded inner layer, and the metal plate 12 outside the folded structure is referred to as a folded outer layer. The upper cover 2 is located above the lower housing 1. In the flange 4 structure of the lower housing 1, the uppermost lamination 40 close to the upper cover 2 is referred to as a top lamination 40. When the flange 4 is an even number of the laminations 40 structure, the outer layer of the top lamination 40 is the metal plate 12, which can be directly welded with the upper cover 2. The insulating layer 11 is the folded inner layer, which is sandwiched between the folded outer layer of the metal plate 12. When the upper cover 2 is welded with the insulating layer 11, the upper cover 2 does not directly contact the insulating layer 11, and thus the insulating layer 11 does not need to be cut.

[0028] In some embodiments, as shown in Figure 1 and Figure 2 The width of the top lamination 40 is 4 mm-8 mm, i.e., the width of the outer metal plate 12 of the top lamination 40 is 4 mm-8 mm. Thus, the welding area of the upper cover 2 and the metal plate 12 can be larger to ensure the welding strength. Specifically, the lamination 40 of the flange is a ring structure around the opening of the lower housing 1, and the width of the lamination 40 refers to the distance between the inner side edge and the outer side edge of the lamination 40.

[0029] In some embodiments, as shown in Figure 1 and Figure 2 The bending part between the laminations 40 of the flange 4 is in a circular arc shape, i.e., the folded bending area of the flange 4 is in a circular arc shape. The design of the circular arc shape can avoid the bending part being too sharp and ensure the safety of production.

[0030] In some embodiments, as shown in Figure 1 The thickness of the insulating layer 11 is 0.01 mm-0.3 mm, and the insulating performance is good, thereby achieving the effect of protecting the safety of battery production.

[0031] In some embodiments, as shown in Figure 1As shown, the material of the metal plate 12 can be aluminum; of course, the material of the metal plate 12 is not limited to aluminum, but can also be other metal materials, such as stainless steel; the material of the insulating layer 11 can be one or more of thermoplastic resin, epoxy resin, polyurethane, silicone, fluorocarbon paint, and acrylate, or other insulating materials.

[0032] Based on the same inventive concept as the battery shell of the present application, the embodiments of the present application also provide a method for manufacturing a battery shell, as shown in Figure 4 The method comprises:

[0033] Step 101, as shown in (a) of Figure 3 , the insulating layer 11 is arranged on one side surface of the metal plate 12;

[0034] Step 102, as shown in (a) and (b) of Figure 3 , the metal plate 12 provided with the insulating layer 11 is subjected to stamping forming to form the shape of the shell 3, the opening of the shell 3 has a flange 31, and the insulating layer 11 is located on the side of the metal plate 12 facing the inside of the shell 3;

[0035] Step 103, as shown in (b) and (c) of Figure 3 , the flange 31 is subjected to bending treatment to form a flange 4 with a folded structure, the folded outer layer of the flange 4 is the metal plate 12, and the folded inner layer is the insulating layer 11;

[0036] Step 104, as shown in (d) of Figure 3 , the upper cover 2 is welded with the metal plate 12 of the folded outer layer of the flange 4.

[0037] In some embodiments, in step 101, the insulating layer 11 is arranged on one side surface of the metal plate 12, specifically comprising: using one of the following ways of pasting, coating and spraying to cover the insulating layer 11 on the inner surface of the metal plate 12.

[0038] Specifically, the insulating layer 11 can also be covered on the inner surface of the metal plate 12 in other ways, and the insulating layer 11 is covered on the inner surface of the metal plate 12 before the metal plate 12 is subjected to stamping forming, so that the insulating layer 11 can be completely attached to the metal plate 12, facilitating subsequent process treatment.

[0039] In some embodiments, the upper cover 2 is welded with the metal plate 12 of the folded outer layer of the flange 4; specifically comprising:

[0040] The metal plate 12 and the upper cover 2 are welded by laser or ultrasonic welding.

[0041] Specifically, the upper cover 2 is welded with the metal plate 12 of the flange 4 folding outer layer, which avoids the contact between the upper cover 2 and the insulating layer 11 during welding, i.e. avoids the process treatment of cutting the insulating layer 11 according to specific size, and facilitates the industrial production.

[0042] The embodiment of the present application also provides a battery comprising the battery shell of any one of the above, the production process of the battery shell is simpler, thereby facilitating the industrial production of the battery using the battery shell; and since the connection strength of the battery shell is higher and the sealing performance is better, the safety performance of the battery is better.

[0043] Obviously, various modifications and changes can be made to the present application by those skilled in the art without departing from the spirit and scope of the present application. Thus, if these modifications and changes of the present application fall within the scope of the present application's claims and their equivalents, it is intended to include these modifications and changes in the present application.

Claims

1. A battery casing, characterized in that, The device includes a lower housing and a top cover. The top cover covers the opening of the lower housing. The lower housing is integrally formed from a sheet metal, which includes a metal plate and an insulating layer on the inner surface of the metal plate. The opening edge of the lower housing has a flange, which is a folded structure formed by bending the sheet metal. The outer folded layer of the flange is a metal plate, and the inner folded layer is an insulating layer. The top cover is welded to the metal plate of the outer folded layer of the flange. The stacked layers of the flange are parallel to the plane where the opening of the lower housing is located. The top stacked layer of the top cover is welded to the flange.

2. The battery casing as described in claim 1, characterized in that, The width of the top layer is 4mm-8mm.

3. The battery casing as described in claim 1, characterized in that, The bends between the stacked flanges are arc-shaped.

4. The battery casing as described in claim 1, characterized in that, The thickness of the insulating layer is 0.01mm-0.3mm.

5. The battery casing as described in any one of claims 1 to 4, characterized in that, The flange comprises two stacks.

6. A method for preparing a battery casing, applicable to the battery casing as described in any one of claims 1 to 5, characterized in that, include: An insulating layer is placed on one side surface of the metal plate; A metal plate with an insulating layer is stamped to form a shell shape, the opening of the shell having a folded edge, and the insulating layer being located on the side of the metal plate facing the interior of the shell; The folded edge is bent to form a flange with a folded structure. The outer folded layer of the flange is a metal plate, and the inner folded layer is an insulating layer. The top cover is welded to the folded outer metal plate of the flange.

7. The method for preparing the battery casing as described in claim 6, characterized in that, The insulating layer is disposed on one side surface of the metal plate; Specifically, it includes: The insulating layer is applied to the inner surface of the metal plate by one of the following methods: lamination, coating, or spraying.

8. The method for preparing the battery casing as described in claim 6 or 7, characterized in that, The welding of the upper cover to the folded outer metal plate of the flange specifically includes: The metal plate and the top cover are welded together using laser or ultrasonic welding.

9. A battery, characterized in that, Includes the battery casing as described in any one of claims 1 to 5.

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