A method for manufacturing a metal battery case

Abstract

The application provides a metal battery shell manufacturing method, which comprises the following steps: manufacturing a first shell body with an opening, wherein the first shell body comprises a top portion and a side wall extending downward from the top portion; connecting a reinforcing plate with the side wall, and making the lower end of the reinforcing plate beyond the lower end of the side wall to form a mounting portion; assembling a second shell body on the mounting portion; and connecting the first shell body, the second shell body and the reinforcing plate at the junctions of the three to obtain a battery shell. The metal battery shell manufacturing method provided by the application is simple in process, and the side wall of the battery shell has high strength and is not easy to deform.

Description

Technical Field

[0001] This invention belongs to the field of battery technology and relates to a method for preparing a metal battery casing. Background Technology

[0002] With the rapid development of portable electronic products, the requirements for batteries used in portable electronic products are also getting higher and higher. While pursuing miniaturization, it is also required that the battery's battery life be improved. This makes the batteries used in portable electronic products have higher energy density, and metal-cased batteries have relatively higher energy density.

[0003] Currently, metal-cased batteries typically consist of an upper casing and a lower casing. To ensure the connection strength and sealing between the upper and lower casings, a stepped stop is usually made at the end of the lower casing to facilitate the fitting and welding of the upper and lower casings. This method is complex and requires a lot of time to make the stepped stop, which is not conducive to simplifying the product manufacturing process. Summary of the Invention

[0004] The metal battery casing preparation method provided by this invention solves, to some extent, the problem of complex manufacturing processes in the prior art for metal battery casings.

[0005] To solve the above-mentioned technical problems, the present invention discloses the following technical solution:

[0006] A method for preparing a metal battery casing includes the following steps:

[0007] Fabricate a first housing with an opening, such that the first housing has a top and a sidewall extending in a straight line from the top to one side thereon;

[0008] The reinforcing plate is connected to the side wall, and the lower end of the reinforcing plate extends beyond the lower end of the side wall to form a mounting portion;

[0009] The edge of the second housing abuts against the lower end face of the side wall and the lower end of the side of the reinforcing plate, respectively, so as to assemble the second housing onto the mounting part to close the opening;

[0010] The reinforcing plate, the side wall, and the second housing are connected by laser welding, and a second welding area is formed between the reinforcing plate, the side wall, and the second housing.

[0011] The step of "connecting the reinforcing plate to the side wall" specifically includes the following steps:

[0012] The reinforcing plate is connected to the side wall by laser welding, and a first welding area is formed between the reinforcing plate and the side wall. The first welding area is located at the upper end of the side wall.

[0013] The thickness of the first shell and the second shell ranges from 20 to 150 μm, the thickness of the reinforcing plate ranges from 75 to 150 μm, and the thickness of the reinforcing plate is greater than or equal to the thickness of the first shell.

[0014] The height of the mounting portion is less than or equal to the thickness of the second housing.

[0015] Furthermore, the height of the mounting portion extending along the sidewall ranges from 20 to 150 μm.

[0016] Furthermore, the reinforcing plate is connected to the first housing and the second housing by welding or bonding.

[0017] Furthermore, the width of the first welding area is 0.05~0.5 mm, and the effective penetration depth of the first welding area on the sidewall is ⅓~⅔ of the sidewall thickness. The distance from the outer edge of the first welding area to the edge of the reinforcing plate is 0.1~1.5 mm.

[0018] Furthermore, the width of the second welding area ranges from 0.1 to 0.4 mm, and the penetration depth of the second welding area ranges from 0.05 to 0.2 mm.

[0019] Furthermore, the metal sheet is stamped and then cut to form the first housing.

[0020] Furthermore, an injection hole is formed on the side wall connected to the reinforcing plate, and the side wall is connected to the reinforcing plate in the circumferential direction of the injection hole.

[0021] The beneficial technical effects of this invention are as follows:

[0022] The reinforcing plate is connected to the side wall of the first housing, and the lower end of the reinforcing plate extends beyond the lower end of the side wall to form a stepped mounting part, which facilitates the assembly and connection between the second housing, the first housing, and the reinforcing plate. This design makes the production process simple and feasible, improves production efficiency, and the connection between the reinforcing plate and the side wall also enhances the strength of the side wall and prevents the side wall from deforming during production and handling.

[0023] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0024] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the disclosure, but do not constitute a limitation thereof. In the drawings:

[0025] Figure 1This is a flowchart of the method for preparing the metal battery casing of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of a metal battery casing provided in an exemplary embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the welding between the sidewall and the reinforcing plate provided in an exemplary embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the welding of the sidewall, the second shell, and the reinforcing plate according to an exemplary embodiment of the present invention. Detailed Implementation

[0029] To facilitate understanding of the invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0030] It should be noted that when an element is described as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is described as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes and do not represent the only possible implementation.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing embodiments and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] Due to the numerous advantages of using ultra-thin metal sheets as battery casings, such as excellent heat dissipation and small footprint, the trend of using ultra-thin metal-cased batteries is becoming increasingly apparent. The wall thickness of these ultra-thin metal casings is typically only tens to hundreds of micrometers, thus presenting significant challenges in their manufacturing process. Battery casings differ from ordinary casings, and the welding process for ultra-thin metals also differs from that of ordinary steel plates. Meeting requirements for sealing, connection strength, and space utilization at such an ultra-thin thickness necessitates improvements in the structural design and welding processes of the battery casing.

[0033] One embodiment of a method for preparing a metal battery casing includes the following steps:

[0034] Fabricate a first housing with an opening, and the first housing includes a top and a sidewall extending in a straight line from the top to one side thereon;

[0035] The reinforcing plate is connected to the side wall, and the lower end of the reinforcing plate extends beyond the lower end of the side wall to form a mounting portion;

[0036] The second housing is assembled onto the mounting portion to close the opening;

[0037] The first housing, the second housing, and the reinforcing plate are connected at their junctions to obtain the battery casing.

[0038] like Figure 1 As shown, to better understand the above-described method for preparing a metal battery casing, the following further explains the method. This embodiment uses a method for preparing a metal battery casing. In one embodiment, the method includes some or all of the following steps:

[0039] S100: Fabricate a first housing with an opening, such that the first housing has a top and a sidewall extending linearly from the top to one side. Specifically, the first housing is obtained by stamping a thin metal sheet and then cutting off the flange edge. The cutting method can be laser cutting or die cutting, etc., that is, the first housing is a one-piece molded part, and the sidewall is perpendicular to the top.

[0040] S200: Connect the reinforcing plate to the side wall, and make the lower end of the reinforcing plate extend beyond the lower end of the side wall to form a mounting portion. In this step, the reinforcing plate is placed against the side wall, the upper end of the reinforcing plate is connected to the side wall, and the lower end of the reinforcing plate extends beyond the lower end of the side wall, i.e., the lower end of the side wall is higher than the lower end of the reinforcing plate. This creates a stepped mounting portion between the lower end of the side wall and the lower end of the reinforcing plate.

[0041] S300: Assemble the second housing onto the mounting portion. This step specifically involves placing the edge of the second housing onto the mounting portion, such that the edge of the second housing abuts against the lower end face of the side wall and the lower end of the side face of the reinforcing plate, respectively. The edge of the second housing refers to the peripheral portion of the second housing body away from the center of the second housing.

[0042] S400: Connect the first housing, the second housing, and the reinforcing plate at their junctions to obtain the battery casing. Specifically, as described in step S300, the junctions of the first housing, the second housing, and the reinforcing plate—namely, the lower end of the sidewall, the lower end of the reinforcing plate, and the edge of the second housing—are interconnected. After connection, the second housing closes the opening of the first housing, thus obtaining the metal battery casing.

[0043] In this embodiment, the thickness of the first shell and the second shell ranges from 20 to 150 μm, and the thickness of the reinforcing plate ranges from 75 to 150 μm. If the thickness of the reinforcing plate is less than the thickness of the first shell, the support provided by the reinforcing plate will not be significant. Therefore, it is necessary to set the thickness of the reinforcing plate to be greater than or equal to the thickness of the first shell. Thus, in this embodiment, the thickness of the first shell and the second shell is 50 μm, and the thickness of the reinforcing plate is 75 μm.

[0044] In this embodiment, the height of the mounting portion extending along the sidewall ranges from 20 to 150 μm. In this embodiment, the height of the mounting portion is selected based on the thickness of the second housing. Typically, the height of the mounting portion is less than or equal to the thickness of the second housing, and preferably the height of the mounting portion is 50 μm.

[0045] In this embodiment, the reinforcing plate is connected to the first housing and the second housing by welding or bonding.

[0046] In this embodiment, laser welding is used to connect the reinforcing plate to the sidewall, forming a first welding area between the reinforcing plate and the sidewall. The laser irradiation direction is perpendicular to the reinforcing plate and the sidewall. Laser welding is a welding method that uses a high-energy-density laser beam as a heat source. It has the advantages of high efficiency and low energy consumption and is suitable for thin plate welding. The portion of the reinforcing plate irradiated by the laser melts completely, and the sidewall melts along its thickness direction in ⅓~⅔. The two molten portions combine to form the first welding area. The first welding area is located at the upper end of the sidewall and extends circumferentially along the sidewall. It can be understood that the reinforcing plate is arranged around the sidewall, and the first welding area is between the reinforcing plate and the sidewall. Therefore, the second welding area extends circumferentially along the sidewall.

[0047] In this embodiment, the width of the first welding area ranges from 0.1 to 0.5 mm, and the effective penetration depth of the first welding area on the sidewall is ⅓ to ⅔ of the sidewall thickness. The effective penetration depth refers to the depth of melting on the sidewall. The width of the first welding area refers to the dimension perpendicular to its extension direction on the outer surface of the sidewall. The width direction of the first welding area is perpendicular to the effective penetration depth direction. For plates of different thicknesses, the required welding width varies. The thicker the plate, the wider the required first welding area and the greater the effective penetration depth. The thinner the plate, the smaller the required first welding area and the greater the effective penetration depth. The narrower the welding area and the shallower the effective penetration depth, the better. Preferably, the width of the first welding area is 0.15 mm and the effective penetration depth is 25 μm. In addition, during welding, a clamp is needed to press down the edges of the reinforcing plate and the side wall to ensure that the reinforcing plate and the side wall fit tightly to achieve a better welding effect. If the reserved width is too narrow, it will be difficult for the clamp to press down the edges of the reinforcing plate and the side wall. If the reserved width is too wide, it will be easy to lift up and affect the assembly. Therefore, the distance from the outer edge of the first welding area to the edge of the reinforcing plate is 0.1~1.5 mm, with a preferred value of 0.2 mm.

[0048] In this embodiment, laser welding is also used to connect the reinforcing plate, the side wall, and the second housing. The laser irradiation direction is parallel to the extension direction of the side wall. The laser irradiates the junction of the reinforcing plate, the side wall, and the second housing, causing the junction to melt. After the junction melts, it combines to form the second welding area, thereby achieving the interconnection of the three. The second welding area extends circumferentially along the side wall.

[0049] It is understood that the junction of the reinforcing plate, the sidewall, and the second housing includes the interface between the reinforcing plate, the sidewall, and the second housing, as well as at least a portion of the reinforcing plate, the sidewall, and the second housing. The at least a portion of the reinforcing plate, the sidewall, and the second housing refers to the part of each of the three near the interface. During welding, the laser irradiates the junction of the reinforcing plate, the sidewall, and the second housing, causing the parts of the three near the interface to melt and fill the interface.

[0050] In this embodiment, the width of the second welding area ranges from 0.05 to 0.3 mm, and the penetration depth of the second welding area ranges from 0.05 to 0.2 mm. Similarly, the width of the second welding area refers to the dimension perpendicular to the extension direction of the outer surface of the sidewall, and the width direction of the second welding area is perpendicular to the penetration depth direction. The penetration depth refers to the depth of melting of the entire second welding area. Preferably, the width of the second welding area is 0.1 mm, and the penetration depth is 0.15 mm.

[0051] In this embodiment, the metal sheet is stamped and then cut to form the first housing. The first housing is formed by stamping a thin metal sheet and then cutting off the flange edge. The stamping and cutting methods used are common processing methods, which will not be described in detail here.

[0052] In this embodiment, the metal sheet is cut to a preset width and a preset length and then bent to obtain the reinforcing plate. The preset width and preset length are determined according to the width and perimeter of the side wall. The preset width and preset length satisfy the condition that the lower end of the reinforcing plate extends beyond the lower end of the side wall and the reinforcing plate can surround the side wall.

[0053] In this embodiment, the second housing can be understood as a cover plate, and the second housing can be made by stamping or cutting metal sheets.

[0054] In this embodiment, an injection hole is provided on the side wall connected to the reinforcing plate, and the side wall is connected to the reinforcing plate in the circumferential direction of the injection hole.

[0055] It should be noted that the directions mentioned in this invention, such as up, down, inside, and outside, refer to the top of the first shell as the upper direction, the second shell as the lower direction, and other areas other than the internal area of ​​the battery shell as the outside.

[0056] The present invention will now be described in detail through specific embodiments.

[0057] First, a 50μm thick sheet of 316L stainless steel is stamped to obtain a shell blank with an opening. The blank is then cut to remove excess scrap, resulting in the first shell. The first shell has a top and a sidewall extending vertically downwards from the top. The sidewall is perpendicular to the top. A 50μm thick sheet of 316L stainless steel is then cut to obtain a flat second shell, or a 50μm thick sheet of 316L stainless steel is stamped to obtain a second shell that is concave from one side to the other. A 75μm thick sheet of 316L stainless steel is then cut to obtain a reinforcing plate of a preset width and preset length. The preset width is such that the width of the reinforcing plate is slightly greater than the height of the sidewall, so as to form an mounting part in later steps. The preset length is such that the reinforcing plate can just wrap around the sidewall.

[0058] Then, the prepared reinforcing plate is attached to the side wall of the first housing, and the lower end of the reinforcing plate is lower than the lower end of the side wall to form a stepped mounting part. The upper end of the reinforcing plate is then connected to the upper end of the side wall by laser welding.

[0059] Finally, the second housing is assembled into the mounting part and the opening is closed, that is, the edge of the second housing abuts against the lower end face of the side wall and the side of the lower end of the reinforcing plate, respectively. Then, the edge of the second housing is connected to the lower end face of the side wall and the side of the lower end of the reinforcing plate by laser welding to obtain the metal battery case.

[0060] Secondly, an injection hole is made on the side wall, the injection hole penetrates the side wall and the reinforcing plate, and the side wall and the reinforcing plate are connected by laser welding in the circumference of the injection hole to prevent liquid from entering between the side wall and the reinforcing plate during injection, thereby affecting the stability of the connection between the reinforcing plate and the side wall.

[0061] The metal battery casing manufacturing method provided by the present invention forms a stepped mounting part by connecting a reinforcing plate to the side wall. This mounting part facilitates the assembly of the second casing with the first casing and the reinforcing plate. This design simplifies the production process, improves production efficiency, and also enhances the strength of the side wall, preventing deformation of the side wall during production and handling.

[0062] The present invention also provides a metal battery casing 10, the battery casing 10 including a first shell 11, a second shell 12 and the reinforcing plate 13, the first shell including a side wall 112, the side wall 112, the second shell 12 and the reinforcing plate 13 being connected by the above-described metal battery casing preparation method to obtain the metal battery casing 10.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a metal battery casing, characterized in that, Includes the following steps; Fabricate a first housing with an opening, such that the first housing has a top and a sidewall extending in a straight line from the top to one side thereon; The reinforcing plate is connected to the side wall, and the lower end of the reinforcing plate extends beyond the lower end of the side wall to form a mounting portion; The edge of the second housing abuts against the lower end face of the side wall and the lower end of the side face of the reinforcing plate, respectively, so as to assemble the second housing onto the mounting part to close the opening; The reinforcing plate, the side wall, and the second housing are connected together, and a second welding area is formed between the reinforcing plate, the side wall, and the second housing; The step of "connecting the reinforcing plate to the side wall" specifically includes the following steps: The reinforcing plate is connected to the side wall by laser welding, and a first welding area is formed between the reinforcing plate and the side wall. The first welding area is located at the upper end of the side wall. The thickness of the first shell and the second shell ranges from 20 to 150 μm, the thickness of the reinforcing plate ranges from 75 to 150 μm, and the thickness of the reinforcing plate is greater than or equal to the thickness of the first shell. The height of the mounting portion is less than or equal to the thickness of the second housing.

2. The method for preparing a metal battery casing according to claim 1, characterized in that, The height of the mounting portion extending along the sidewall ranges from 20 to 150 μm.

3. The method for preparing a metal battery casing according to claim 1, characterized in that, The reinforcing plate is connected to the first shell and the second shell by welding or bonding.

4. The method for preparing a metal battery casing according to claim 1, characterized in that, The width of the first welding area is 0.05~0.5 mm, the effective penetration depth of the first welding area is ⅓~⅔ of the sidewall thickness, and the distance from the outer edge of the first welding area to the edge of the reinforcing plate is 0.1~1.5 mm.

5. The method for preparing a metal battery casing according to claim 1, characterized in that, The step of connecting the reinforcing plate, the side wall, and the second housing, and forming a second welding area between the reinforcing plate, the side wall, and the second housing specifically includes the following steps: The reinforcing plate, the side wall, and the second housing are connected by laser welding, and a second welding area is formed between the three components.

6. The method for preparing a metal battery casing according to claim 5, characterized in that, The width of the second welding area ranges from 0.1 to 0.4 mm, and the penetration depth of the second welding area ranges from 0.05 to 0.2 mm.

7. The method for preparing a metal battery casing according to claim 1, characterized in that, The step of fabricating a first shell with an opening specifically includes the following: The metal sheet is stamped and then cut to form the first housing.

8. The method for preparing a metal battery casing according to claim 1, characterized in that, An injection hole is made on the side wall connected to the reinforcing plate, and the side wall is connected to the reinforcing plate in the circumferential direction of the injection hole.

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