Cylindrical battery tab manufacturing method

Abstract

The invention belongs to the technical field of new energy batteries, and particularly relates to a cylindrical battery tab manufacturing method which comprises the following steps: S1, slitting; s2, continuous laser cutting; s3, cutting a negative electrode; s4, pre-folding is carried out; s5, winding; s6, the tabs are folded; in the step S1, foil materials of a certain size are reserved on the edges of the cut positive and negative pole pieces to serve as tabs, in the step S2, the reserved foil materials of the positive and negative poles are continuously cut through laser, and a positive pole cutting scheme is designed according to the Archimedes spiral theorem: the length of a tab-free area at the front end of the pole piece is 545 mm, the tabs on the pole piece are divided into 13 areas, the tab cutting height of the first area is 5 mm, the tab cutting height of the second area is 5 mm, and the tab cutting height of the third area is 5 mm. The tab height of the rest area is 6 mm, and the tab-free area at the tail part of the pole piece is 300 mm; according to the tab manufacturing method, 0.5 mm and 1 mm are reserved for the positive electrode and the negative electrode of the tab root respectively, it is proved according to experimental results that diaphragm hot melting caused by welding of the positive electrode collector plate and the negative electrode collector plate can be effectively avoided, and the yield of subsequent procedures is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy batteries, and in particular to a method for manufacturing a cylindrical battery tab. Background Art

[0002] In order to improve the rate performance of large cylindrical batteries, the number of tabs needs to be increased. The common methods currently on the market are as follows:

[0003] 1. Use the flattening method to flatten the reserved current collector through a high-speed ceramic wheel. This method occupies the height direction of the two ends of the battery cell and reduces the battery cell capacity; flattening brings a lot of metal chips, which reduces battery performance and has a high safety risk; the flattened end surface is compacted, so it is difficult to inject liquid and infiltrate, which increases the battery process time and reduces efficiency;

[0004] 2. Slit-cut tabs. Compared with the patented technology, this technology has poor flatness after the end face of the battery cell is flattened, and the number of tab stacking layers in each area varies greatly. The subsequent welding is easy to melt the diaphragm, and a higher foil isolation diaphragm needs to be reserved, which reduces the capacity of the battery cell.

[0005] In summary, the existing large cylindrical battery tab design has problems such as poor surface formation, difficulty in injection, and low safety performance. Summary of the invention

[0006] The purpose of this application is to provide a method for manufacturing a cylindrical battery tab to solve the problems raised in the above background technology.

[0007] The present invention provides a method for manufacturing a cylindrical battery tab, comprising the following steps:

[0008] S1: Slitting;

[0009] S2: continuous laser cutting;

[0010] S3: negative electrode cutting;

[0011] S4: pre-fold;

[0012] S5: winding;

[0013] S6: The tabs are folded;

[0014] S7: Flatten.

[0015] Preferably, in step S1, foil of a certain size is reserved at the edges of the cut positive and negative electrode sheets as tabs.

[0016] Preferably, in the step S2, the reserved foils of the positive and negative electrodes are continuously laser cut, and the positive electrode cutting scheme is designed according to the Archimedean screw theorem: the length of the area without pole lugs at the front end of the pole piece is 545 mm, the pole lugs on the pole piece are divided into 13 areas, the pole lug height of the first area is 5 mm, and the pole lug height of the remaining areas is 6 mm. The area without pole lugs at the tail of the pole piece is 300 mm; the reserved height of the foil root is designed to be 0.5 mm according to actual results.

[0017] Preferably, in the step S3, the negative electrode cutting plan is as follows: the length of the area without a pole lug at the front end of the pole piece is 550 mm, the pole lug on the pole piece is divided into 13 areas, the pole lug height of the first area is 5 mm, the pole lug height of the remaining areas is 6 mm, and the area without a pole lug at the tail of the pole piece is 275 mm; the reserved height of the foil root is designed to be 1 mm according to actual results.

[0018] Preferably, in the step S4, a pre-folding wheel is used to pre-fold the lug root by 75°.

[0019] Preferably, in the step S5, the separator is rolled first, and then the negative electrode and the positive electrode are rolled in. The winding is carried out into the designed size of the battery cell and then cut.

[0020] Preferably, in the step S6, the positive and negative electrode tabs are folded to 45° using a folding mechanism.

[0021] Preferably, in the step S7, a flattening mechanism is used to flatten the end faces of the battery cells.

[0022] The beneficial effects of the present invention are:

[0023] 1. The tabs are cut from the reserved foil of the pole piece, replacing the traditional method of welding metal tabs on the pole piece, which effectively improves the space utilization of the active material and the roundness of the cylindrical winding core, and greatly reduces the internal resistance of the battery;

[0024] 2. The method for manufacturing the tabs of the present invention defines the tab heights and angles in different areas, thereby avoiding the interference between the tabs caused by the small diameter of the inner ring battery core, making the subsequent end face molding surface smoother, the tabs arranged in an orderly manner, and the subsequent end face collector plate laser welding effect better and the yield higher;

[0025] 3. In the method for manufacturing the tabs of the present invention, no metal debris enters the battery, thus avoiding the subsequent low voltage failure, Hi-pot failure and possible short circuit risks; and the presence of a small gap between the tabs is more conducive to the subsequent electrolyte infiltration, reducing the injection time and improving the process efficiency;

[0026] 4. In the method for manufacturing the tab of the present invention, 0.5 mm and 1 mm are reserved for the positive and negative electrodes at the root of the tab respectively. Experimental results show that this can effectively avoid the hot melting of the diaphragm caused by the welding of the positive and negative current collecting plates, thereby improving the yield of subsequent processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the structure of a positive electrode tab of a cylindrical battery tab proposed by the present invention;

[0028] Figure 2 A schematic diagram of the structure of a negative electrode tab of a cylindrical battery tab proposed by the present invention;

[0029] Figure 3 A schematic diagram of the winding structure of a cylindrical battery tab proposed by the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further explained below in conjunction with specific embodiments.

[0031] refer to Figure 1-3 In this embodiment, a method for manufacturing a cylindrical battery tab is proposed, comprising the following steps:

[0032] S1: Slitting;

[0033] S2: continuous laser cutting;

[0034] S3: negative electrode cutting;

[0035] S4: pre-fold;

[0036] S5: winding;

[0037] S6: The tabs are folded;

[0038] S7: Flatten.

[0039] In this embodiment, in step S1, a certain size of foil is reserved at the edges of the cut positive and negative electrode sheets as electrode tabs.

[0040] In this embodiment, in step S2, the reserved foils of the positive and negative electrodes are continuously laser cut, and the positive electrode cutting scheme is designed according to the Archimedean screw theorem: the length of the area without pole ears at the front end of the pole piece is 545 mm, the pole ears on the pole piece are divided into 13 areas, the pole ears height of the first area is 5 mm, and the pole ears height of the remaining areas are 6 mm. The area without pole ears at the tail of the pole piece is 300 mm; the reserved height of the foil root is designed to be 0.5 mm according to the actual results.

[0041]

[0042]

[0043] In this embodiment, in step S3, the negative electrode cutting plan is: the length of the area without pole lugs at the front end of the pole piece is 550mm, the pole lugs on the pole piece are divided into 13 areas, the pole lug height of the first area is 5mm, and the pole lug height of the remaining areas is 6mm. The area without pole lugs at the tail of the pole piece is 275mm; the reserved height of the root of the foil is designed to be 1mm according to the actual results.

[0044]

[0045]

[0046] In this embodiment, in step S4, a pre-folding wheel is used to pre-fold the base of the tab by 75°.

[0047] In this embodiment, in step S5, the separator is rolled first, and then the negative electrode and the positive electrode are rolled. The winding is carried out into the designed size of the battery cell and then cut.

[0048] In this embodiment, in step S6, the positive and negative electrode tabs are retracted to 45 degrees using a retracting mechanism.

[0049] In this embodiment, in step S7, a flattening mechanism is used to flatten the end surface of the battery cell.

[0050] Working principle: When in use, the positive and negative pole ears are set on one side of the battery cell. The positive and negative pole ears are cut into multiple pole ears through the cut pole pieces. The foil current collector reserved after the pole pieces are coated is cut into multiple pole ears. The foil is cut by continuous laser in a planned path to form "T"-shaped pole ears of different heights. The length of the area without pole ears and the height, width and trapezoidal angle of the pole ears in different areas are designed according to the diameter of the battery cell. After cutting, they are pre-bent and flattened.

[0051] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for manufacturing a cylindrical battery tab, characterized in that: The following steps are involved: S1: Slitting; S2: continuous laser cutting; S3: negative electrode cutting; S4: pre-fold; S5: winding; S6: The tabs are folded; S7: Flatten.

2. A method for manufacturing a cylindrical battery tab according to claim 1, characterized in that: In the step S1, a certain size of foil is reserved at the edges of the cut positive and negative electrode sheets as electrode ears.

3. The method for manufacturing a cylindrical battery tab according to claim 1, characterized in that: In the step S2, the reserved foils of the positive and negative electrodes are continuously laser cut, and the positive electrode cutting scheme is designed according to the Archimedean screw theorem: the length of the area without pole ears at the front end of the pole piece is 545 mm, and the pole ears on the pole piece are divided into 13 areas. The pole ears height of the first area is 5 mm, and the pole ears height of the remaining areas are 6 mm. The area without pole ears at the tail of the pole piece is 300 mm; the reserved height of the foil root is designed to be 0.5 mm according to the actual results.

4. The method for manufacturing a cylindrical battery tab according to claim 1, characterized in that: In the step S3, the negative electrode cutting plan: the length of the area without pole lugs at the front end of the pole piece is 550mm, the pole lugs on the pole piece are divided into 13 areas, the pole lug height of the first area is 5mm, the pole lug height of the remaining areas is 6mm, and the area without pole lugs at the tail of the pole piece is 275mm; the reserved height of the root of the foil is designed to be 1mm according to the actual results.

5. The method for manufacturing a cylindrical battery tab according to claim 1, characterized in that: In the step S4, a pre-folding wheel is used to pre-fold the base of the tab by 75°.

6. The method for manufacturing a cylindrical battery tab according to claim 1, characterized in that: In the step S5, the separator is rolled first, followed by the negative electrode and the positive electrode, and the winding is performed into the designed size of the battery cell and then cut.

7. The method for manufacturing a cylindrical battery tab according to claim 1, characterized in that: In the step S6, the positive and negative electrode tabs are folded to 45 degrees using a folding mechanism.

8. The method for manufacturing a cylindrical battery tab according to claim 1, characterized in that: In the step S7, a flattening mechanism is used to flatten the end surface of the cell.

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