Electroplating method of cylindrical battery shell plate

Abstract

The invention discloses an electroplating method for a cylindrical battery shell plate, which comprises the following steps: providing a plate, dividing the plate into a non-electroplating area and a plurality of electroplating areas, and stamping and stretching the electroplating areas after electroplating to form a cylindrical battery shell; according to the forming requirement of the shell, the electroplating area is sequentially divided into a plurality of machining areas from inside to outside; electroplating metal is used for electroplating the machining areas of the electroplating area, and when any machining area of the electroplating area is electroplated, the insulation attaching pieces are attached to the other machining areas and the non-electroplating area. According to the invention, each processing area can be electroplated in a targeted manner, so that different plating thicknesses can be set for each processing area according to different requirements, and the utilization rate of electroplated metal is improved.

Description

Technical Field

[0001] The present application relates to the field of cylindrical batteries, and in particular to an electroplating method for cylindrical battery shell plates. Background Art

[0002] In the manufacturing process of cylindrical battery casings, nickel and other metals can be plated on the surface of the cylindrical battery casing to achieve corrosion protection and other functions. Taking nickel plating as an example, the electroplating process is divided into two types: pre-plating and post-plating. Pre-plating has advantages over post-plating, such as higher coating adhesion, fewer appearance defects, less iron dissolution, less residual nickel powder during production, and better self-discharge. Therefore, pre-plated nickel steel casings are widely used in high-rate power lithium battery products.

[0003] However, due to the influence of the electroplating process, after the pre-nickel-plated sheet is stretched into a shell, the shell's plating is also stretched. This will result in the plating at both ends of the shell's side walls being slightly stretched, the plating in the middle of the shell's side walls being moderately stretched, and the plating on the shell's bottom being unstretched. The stretched plating becomes thinner, and its anti-corrosion protection for the shell is reduced. This also leads to a "barrel effect" in the corrosion resistance of the pre-nickel-plated steel shell, which reduces the overall corrosion resistance. In addition, the low electroplating utilization rate of the pre-nickel-plated sheet makes it more difficult to control production costs. If the barrel effect is mitigated by increasing the plating thickness of the pre-nickel-plated sheet, although the shell's corrosion resistance is improved, the plating on the shell bottom will be too thick, making it difficult to weld. In addition, the nickel plate consumption is greater, making the shell production cost higher. Summary of the Invention

[0004] The purpose of this application is to provide an electroplating method for cylindrical battery shell plates, which can plate electroplated metals of different thicknesses on different areas of the cylindrical battery shell, reduce the consumption of electroplated metals, and reduce the production cost of the shell.

[0005] To achieve the above objectives, the present application provides an electroplating method for a cylindrical battery shell plate, comprising: Providing a plate and dividing the plate into a non-electroplating area and a plurality of electroplating areas, wherein the electroplating areas are used for stamping and stretching to form a cylindrical battery shell after electroplating; According to the molding requirements of the shell, the electroplating area is divided into several processing areas from the inside to the outside; The processing areas of the electroplating zone are electroplated with electroplating metal, and when any one of the processing areas of the electroplating zone is electroplated, an insulating bonding sheet is attached to the other processing areas and the non-electroplating area.

[0006] The present application divides the plate into a non-electroplating area and several electroplating areas, and divides the electroplating area into several processing areas from the inside to the outside. When electroplating any processing area of the electroplating area, the insulating bonding sheet is attached to other processing areas and the non-electroplating area, so that the electroplated metal can be attached to the part of the plate where the insulating bonding sheet is not attached, so that each processing area can be electroplated in a targeted manner, so that each processing area can be set with different plating thicknesses according to different needs, thereby improving the utilization rate of the electroplated metal. In addition, the non-electroplating area does not consume the electroplated metal during the electroplating process. After punching the electroplating area, the non-electroplating area can be recycled after normal annealing treatment. Compared with the existing technology, the non-electroplating area of the present application is less difficult to recycle, which is conducive to improving the utilization rate of resources.

[0007] Optionally, attaching the insulating bonding sheet to the other processing areas includes: There is a junction between each adjacent processing area that is not covered by any of the insulating bonding sheets.

[0008] Optionally, the electroplated metal comprises nickel.

[0009] Optionally, according to the forming requirements of the shell, the processing area is divided into at least four types, including a non-stretching zone, a first stretching zone, a second stretching zone and a third stretching zone; wherein the non-stretching zone, the first stretching zone, the second stretching zone and the third stretching zone are connected in sequence from the inside to the outside; the non-stretching zone is used to form the bottom of the shell, the first stretching zone is used to form the bottom of the side wall of the shell, the first stretching zone is used to form the middle of the shell, and the third stretching zone is used to form the top of the side wall of the shell.

[0010] Optionally, the coating thickness of the second stretching zone is greater than the coating thickness of the first stretching zone and the third stretching zone, and the coating thickness of the first stretching zone and the third stretching zone is greater than the coating thickness of the non-stretching zone.

[0011] Optionally, the plating thickness of the side of the electroplating area forming the outer wall of the shell is greater than the plating thickness of the side of the electroplating area forming the inner wall of the shell.

[0012] Optionally, in a side where the electroplating area forms the outer wall of the shell, the plating thicknesses of the non-stretching area, the first stretching area, the second stretching area and the third stretching area are 3.0±0.5 μm, 3.3±0.5 μm, 3.5±0.5 μm and 3.3±0.5 μm respectively; Optionally, in one side of the inner wall of the shell formed by the electroplating area, the plating thicknesses of the non-stretching area, the first stretching area, the second stretching area and the third stretching area are 1.0±0.5μm, 1.3±0.5μm, 1.5±0.5μm and 1.3±0.5μm respectively.

[0013] Optionally, the electroplating area is circular; the processing area located at the center of the electroplating area is circular and has the same center as the electroplating area, and the other processing areas are annular and have the same center as the electroplating area.

[0014] Optionally, the plating thickness of each processing area is controlled by controlling the electroplating current and / or the electroplating time.

[0015] Optionally, the material of the insulating bonding sheet includes at least one of PET, PP and PBT. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of the electroplating method of the cylindrical battery shell plate according to an embodiment of the present application.

[0017] Figure 2 This is a schematic diagram of dividing a plate into a non-electroplating area and an electroplating area in an embodiment of the present application.

[0018] Figure 3 This is a schematic diagram of attaching an insulating bonding sheet to a non-electroplating area in an embodiment of the present application.

[0019] Figure 4 This is a schematic diagram of dividing the electroplating area into processing areas according to an embodiment of the present application.

[0020] Figure 5 This is a schematic diagram of attaching insulating bonding sheets to other processing areas when electroplating is performed in a non-stretching area in the electroplating area according to an embodiment of the present application.

[0021] Figure 6 This is a schematic diagram of the three-dimensional structure of the shell of the cylindrical battery in an embodiment of the present application.

[0022] Figure 7 This is a schematic diagram of an embodiment of the present application in which an insulating bonding sheet is attached to each processing area. DETAILED DESCRIPTION

[0023] In order to explain the technical content, structural features, achieved objectives and effects of this application in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0024] Please refer to 2 to Figure 6In the forming process of the shell 200 of the cylindrical battery, after the plate 100 is electroplated, the multiple electroplated parts on the plate 100 are punched out, and then the punched-out parts are stamped and stretched to form the shell 200. Among them, the electroplated parts of the plate 100 will form the shell bottom 201 and the side wall 202 of the shell 200 during the stamping and stretching process. Among them, the intersection of the shell bottom 201 and the side wall 202 of the shell 200 will be stretched during the forming process, causing the plating at the intersection to become thinner, and the anti-corrosion protection effect of the plating on the shell 200 will be reduced. In addition, during the forming process, different parts of the side wall 202 of the shell 200 will also be stretched to varying degrees. If the plating layer of the plate 100 is uniformly thickened, it will not only increase the difficulty of welding, but also cause waste of electroplating metal used for electroplating. Therefore, the present application divides the electroplated parts of the plate 100 into zones and performs electroplating in a targeted manner.

[0025] For this, see Figures 1 to 6 The present application discloses a method for electroplating a cylindrical battery shell plate, comprising: S1, providing a plate 100, and dividing the plate 100 into a non-electroplating area 1 and a plurality of electroplating areas 2, the electroplating areas 2 are used for stamping and stretching after electroplating to form a cylindrical battery shell 200.

[0026] S2, according to the forming requirements of the housing 200, the electroplating area 2 is divided into a plurality of processing areas 21 from the inside to the outside. The forming requirements may be the degree of deformation of each part of the electroplating area 2 during the forming process of the housing 200, etc., which will not be described in detail.

[0027] S3, using electroplating metal to electroplate each processing area 21 of the electroplating area 2, and when electroplating any processing area 21 of the electroplating area 2, the insulating bonding sheet 3 is attached to other processing areas 21 and the non-electroplating area 1.

[0028] The present application divides the plate 100 into a non-electroplating area 1 and several electroplating areas 2, and divides the electroplating area 2 into several processing areas 21 from the inside to the outside. When electroplating any processing area 21 of the electroplating area 2, the insulating laminating sheet 3 is attached to the other processing areas 21 and the non-electroplating area 1, so that the electroplated metal can be attached to the part of the plate 100 where the insulating laminating sheet 3 is not attached, so that each processing area 21 can be electroplated in a targeted manner, so that each processing area 21 can be set with different coating thicknesses according to different needs, thereby improving the utilization rate of the electroplated metal. In addition, the non-electroplating area 1 does not consume the electroplated metal during the electroplating process. After punching the electroplating area 2, the non-electroplating area 1 can be recycled by performing normal annealing treatment. Compared with the prior art, the non-electroplating area 1 of the present application is less difficult to recycle, which is conducive to improving the utilization rate of resources.

[0029] See also Figure 4 and Figure 6 During the process of forming the shell 200 in the electroplating area 2, the plating at the ends of the sidewalls 202 of the shell 200 will be slightly stretched, the plating in the middle of the sidewalls 202 will be moderately stretched, and the plating on the bottom 201 of the shell 200 will not be stretched. Therefore, the processing area 21 can be divided into multiple areas based on the degree of stretching of different parts of the shell 200 as a preset requirement. During the stretching process of the shell 200, the deformation amount varies greatly between different parts. To avoid damage to the plating after stretching and leakage of steel, composite electroplating can be performed at the intersections between the various areas.

[0030] See also Figure 7 In some embodiments, there is a junction between adjacent processing areas 21 that is not covered by any insulating bonding sheet 3.

[0031] Specifically, see Figure 7 , attaching the insulating laminating sheet 3 to other processing areas 21 includes: The outer diameter of the insulating bonding sheet 3 is smaller than the outer diameter of the other processing area 21 corresponding to the insulating bonding sheet 3, thereby facilitating composite electroplating.

[0032] More specifically, the outer diameter of the insulating laminate 3 is 1-2 mm smaller than the outer diameter of the corresponding other processed areas 21 .

[0033] In some embodiments, the electroplated metal includes nickel. Of course, it is not limited thereto.

[0034] See also Figure 4 and Figure 6 In some embodiments, based on the molding requirements of the housing 200, the processing area 21 is divided into at least four types, including a non-stretching area 211, a first stretching area 212, a second stretching area 213, and a third stretching area 214. The non-stretching area 211, the first stretching area 212, the second stretching area 213, and the third stretching area 214 are sequentially connected from the inside out. The non-stretching area 211 is used to form the bottom 201 of the housing 200, the first stretching area 212 is used to form the bottom of the sidewall 202 of the housing 200, the first stretching area 212 is used to form the middle of the housing 200, and the third stretching area 214 is used to form the top of the sidewall 202 of the housing 200. Of course, this is not limited to this. The coating thickness of each processing area 21 is determined according to actual needs, and the number of processing areas 21 can be adjusted according to the height of the housing 200. For example, the higher the height of the housing 200, the more processing areas 21 are divided to meet the needs of more deformable parts of the housing 200.

[0035] Specifically, the coating thickness of the second stretching zone 213 is greater than the coating thickness of the first stretching zone 212 and the third stretching zone 214 , and the coating thickness of the first stretching zone 212 and the third stretching zone 214 is greater than the coating thickness of the non-stretching zone 211 .

[0036] Since the inner wall of the shell 200 is isolated from the external high temperature and high humidity environment, the required coating thickness is relatively low. The outer wall of the shell 200 is in contact with the external environment and has a large tensile deformation during the molding process, so the required coating thickness is larger.

[0037] Specifically, the plating thickness of the electroplating area 2 forming the outer wall of the housing 200 is greater than the plating thickness of the electroplating area 2 forming the inner wall of the housing 200 .

[0038] Optionally, in one side of the outer wall of the shell 200 formed by the electroplating area 2, the coating thicknesses of the non-stretching area 211, the first stretching area 212, the second stretching area 213 and the third stretching area 214 are 3.0±0.5μm, 3.3±0.5μm, 3.5±0.5μm and 3.3±0.5μm respectively.

[0039] Optionally, in the side of the inner wall of the shell 200 formed by the electroplating area 2, the coating thicknesses of the non-stretching area 211, the first stretching area 212, the second stretching area 213 and the third stretching area 214 are 1.0±0.5μm, 1.3±0.5μm, 1.5±0.5μm and 1.3±0.5μm respectively.

[0040] See also Figure 4 and Figure 6 In some embodiments, the electroplating area 2 is circular; the processing area 21 located at the center of the electroplating area 2 is circular and has the same center as the electroplating area 2, and the other processing areas 21 are annular and have the same center as the electroplating area 2.

[0041] In some embodiments, the plating thickness of each processing area 21 is controlled by controlling electroplating parameters such as electroplating current and / or electroplating time.

[0042] In some embodiments, the material of the insulating bonding sheet 3 includes at least one of insulating, high-temperature-resistant and corrosion-resistant materials such as PET, PP and PBT.

[0043] In some embodiments, the insulating bonding sheet 3 can be fixed on the plate 100 by applying external force, vacuum adsorption, etc. to shield the electroplating reaction and ensure a stable electroplating process.

[0044] See also Figures 1 to 7 In combination with the above embodiments, the electroplating process of the processing area 21 is described below by way of example: Assume that the electroplating material is nickel, and the processing area 21 is divided into four types: non-electroplating area 1, non-stretching area 211, first stretching area 212, second stretching area 213, and third stretching area 214. Among them, non-electroplating area 1, non-stretching area 211, first stretching area 212, second stretching area 213, and third stretching area 214 are respectively provided with insulating bonding sheet 30, insulating bonding sheet 31, insulating bonding sheet 32, insulating bonding sheet 33, and insulating bonding sheet 34.

[0045] Step 1: Stick the insulating bonding sheet 30, the insulating bonding sheet 32, the insulating bonding sheet 33 and the insulating bonding sheet 34 on the non-electroplating area 1, the first stretching area 212, the second stretching area 213 and the third stretching area 214. After setting the plating parameters such as the plating current and the plating time for both sides of the non-stretching area 211, the non-stretching area 211 is electroplated.

[0046] Step 2: remove the insulating bonding sheet 32, attach the insulating bonding sheet 31 to the non-stretching area 211, set the electroplating parameters such as electroplating current and electroplating time for both sides of the first stretching area 212, and then electroplate the first stretching area 212.

[0047] Step 3, remove the insulating bonding sheet 33, attach the insulating bonding sheet 32 to the first stretching area 212, set the electroplating parameters such as electroplating current and electroplating time for both sides of the second stretching area 213, and then electroplate the second stretching area 213.

[0048] Step 4, remove the insulating bonding sheet 34, attach the insulating bonding sheet 33 to the second stretching area 213, set the electroplating parameters such as electroplating current and electroplating time for both sides of the second stretching area 213, and then electroplate the second stretching area 213.

[0049] It can be understood that the order of electroplating the above-mentioned non-stretching zone 211, the first stretching zone 212, the second stretching zone 213 and the third stretching zone 214 is not particular. It is only necessary to remove the insulating adhesive sheet 3 of the processing area 21 to be electroplated before electroplating and attach the corresponding insulating adhesive sheet 3 to the processing area 21 to be electroplated.

[0050] The above disclosure is only the preferred embodiment of the present application, which certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the scope of the patent application of the present application are still within the scope covered by the present application.

Claims

1. A method for electroplating a cylindrical battery shell plate, characterized in that: include: Providing a plate and dividing the plate into a non-electroplating area and a plurality of electroplating areas, wherein the electroplating areas are used for stamping and stretching to form a cylindrical battery shell after electroplating; According to the molding requirements of the shell, the electroplating area is divided into several processing areas from the inside to the outside; The processing areas of the electroplating zone are electroplated with electroplating metal, and when any one of the processing areas of the electroplating zone is electroplated, an insulating bonding sheet is attached to the other processing areas and the non-electroplating area.

2. The electroplating method for cylindrical battery shell plate according to claim 1, characterized in that: The step of attaching the insulating bonding sheet to the other processing areas includes: There is a junction between each adjacent processing area that is not covered by any of the insulating bonding sheets.

3. The electroplating method for cylindrical battery shell plate according to claim 1, characterized in that: The electroplated metal includes nickel.

4. The electroplating method for cylindrical battery shell plate according to claim 1, characterized in that: According to the forming requirements of the shell, the processing area is divided into at least four types, including a non-stretching zone, a first stretching zone, a second stretching zone and a third stretching zone; wherein the non-stretching zone, the first stretching zone, the second stretching zone and the third stretching zone are connected in sequence from the inside to the outside; the non-stretching zone is used to form the bottom of the shell, the first stretching zone is used to form the bottom of the side wall of the shell, the first stretching zone is used to form the middle of the shell, and the third stretching zone is used to form the top of the side wall of the shell.

5. The electroplating method for cylindrical battery shell plate according to claim 4, characterized in that: The coating thickness of the second stretching zone is greater than the coating thickness of the first stretching zone and the third stretching zone, and the coating thickness of the first stretching zone and the third stretching zone is greater than the coating thickness of the non-stretching zone.

6. The electroplating method for cylindrical battery shell plate according to claim 4, characterized in that: The plating thickness of the electroplating area on the side forming the outer wall of the shell is greater than the plating thickness of the electroplating area on the side forming the inner wall of the shell.

7. The electroplating method for a cylindrical battery shell plate according to any one of claims 4 to 6, characterized in that: On one side of the electroplating area forming the outer wall of the shell, the plating thicknesses of the non-stretching area, the first stretching area, the second stretching area, and the third stretching area are 3.0±0.5 μm, 3.3±0.5 μm, 3.5±0.5 μm, and 3.3±0.5 μm, respectively; and / or, In one side of the inner wall of the shell formed by the electroplating area, the plating thicknesses of the non-stretching area, the first stretching area, the second stretching area and the third stretching area are 1.0±0.5μm, 1.3±0.5μm, 1.5±0.5μm and 1.3±0.5μm respectively.

8. The electroplating method for cylindrical battery shell plate according to claim 1, characterized in that: The electroplating area is circular; the processing area located at the center of the electroplating area is circular and has the same center as the electroplating area; the other processing areas are annular and have the same center as the electroplating area.

9. The electroplating method for cylindrical battery shell plate according to claim 1, characterized in that: The plating thickness of each processing area is controlled by controlling the electroplating current and / or the electroplating time.

10. The electroplating method for cylindrical battery shell plate according to claim 1, characterized in that: The material of the insulating bonding sheet includes at least one of PET, PP and PBT.

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