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CN-121983520-A - Preparation method of pole piece, battery cell and preparation method of battery cell

CN121983520ACN 121983520 ACN121983520 ACN 121983520ACN-121983520-A

Abstract

The application provides a preparation method of a pole piece, a battery cell and a preparation method of the battery cell. The preparation method of the pole piece comprises the steps of providing a current collector, preparing an active material layer in the coating area, cutting the current collector along the common edge of the waste area and the coating area and the common edge of the waste area and the tab area, removing the waste area, and forming the tab area into the tab, thereby obtaining the pole piece. According to the preparation method of the pole piece, the active material layer with the specific shape is arranged on the coating area with the specific shape of the current collector, and then the waste area on the current collector is cut off along the edges of the coating area and the tab area by adopting a laser cutting mode, so that the pole piece with the specific shape is obtained.

Inventors

  • CHEN YUHUA
  • ZHAO RUIRUI
  • REN REN
  • LU SHUNLI

Assignees

  • 惠州亿纬锂能股份有限公司

Dates

Publication Date
20260505
Application Date
20251218

Claims (10)

  1. 1. The preparation method of the pole piece is characterized by comprising the following steps: providing a current collector having an interconnected coating region, tab region and waste region; Preparing an active material layer in the coating region; and cutting the current collector along the common edges of the waste region and the coating region and the common edges of the waste region and the tab region by laser to remove the waste region, wherein the tab region is formed into a tab, and a pole piece is obtained.
  2. 2. The method for manufacturing the pole piece according to claim 1, wherein the laser cutting is performed by using pulse laser with a pulse width of 50 fs-50 ps.
  3. 3. The method for preparing a pole piece according to claim 1 or 2, wherein the laser power of the laser cutting is 50-300W, and/or, The cutting turns of the laser cutting are 5-200.
  4. 4. A method of manufacturing a pole piece according to any one of claims 1 to 3, wherein a common edge is provided between the tab region and the coating region, and the length of the common edge between the tab region and the coating region is 0.2 to 0.5 of the circumference of the coating region.
  5. 5. The method of producing a pole piece according to any of the claims 1 to 4, characterized in that the active material layer comprises a nickel cobalt manganese ternary material, and/or, The thickness of the current collector is 4-15 mu m, and/or, The thickness of the pole piece is 50-200 mu m.
  6. 6. The method of producing a pole piece according to any one of claims 1 to 5, further comprising producing a ceramic layer along the edges of the coating region, the ceramic layer surrounding the active material layer, and/or, The coating area is shaped.
  7. 7. The battery cell is characterized by comprising a positive plate, a diaphragm and a negative plate, wherein the diaphragm is positioned between the positive plate and the negative plate, and at least one of the positive plate and the negative plate is prepared by the preparation method of the electrode plate according to any one of claims 1 to 6.
  8. 8. The method for manufacturing a battery cell according to claim 7, wherein the positive tab on the positive electrode sheet is disposed opposite to the negative tab on the negative electrode sheet, and in the thickness direction of the battery cell, the positive projection of the positive tab on the positive electrode sheet is offset from the positive projection of the negative tab on the negative electrode sheet.
  9. 9. The preparation method of the battery cell is characterized by comprising the following steps: providing a pole piece, wherein the pole piece comprises a positive pole piece and a negative pole piece, and the pole piece is prepared by the preparation method of the pole piece according to any one of claims 1 to 6; And stacking the positive plate, the negative plate and a diaphragm, wherein the diaphragm is positioned between the positive plate and the negative plate, so as to obtain the battery cell.
  10. 10. The method of manufacturing a battery cell according to claim 9, wherein the separator is a rubberized separator, and the stacking the positive electrode sheet and the negative electrode sheet with the separator comprises: carrying out hot-pressing compounding on the gluing diaphragm and the negative plate to obtain a negative unit; And carrying out hot-pressing compounding on the negative electrode unit and the positive electrode plate to obtain the battery cell.

Description

Preparation method of pole piece, battery cell and preparation method of battery cell Technical Field The application relates to the technical field of batteries, in particular to a preparation method of a pole piece, an electric core and a preparation method of the electric core. Background At present, in the process of preparing the battery cell, a hardware cutting die cutting mode is mostly adopted for cutting the pole piece, and the cutting mode needs to independently develop dies aiming at pole pieces with different shapes or sizes, so that the cost of changing the shape is increased, and the period is prolonged. Disclosure of Invention The embodiment of the application provides a preparation method of a pole piece, an electric core and a preparation method thereof, which can solve the technical problems of high pole piece preparation cost and long period. The embodiment of the application provides a preparation method of a pole piece, which comprises the following steps: providing a current collector having an interconnected coating region, tab region and waste region; Preparing an active material layer in the coating region; and cutting the current collector along the common edges of the waste region and the coating region and the common edges of the waste region and the tab region by laser to remove the waste region, wherein the tab region is formed into a tab, and a pole piece is obtained. According to the preparation method of the pole piece, the active material layer with the specific shape is arranged on the coating area with the specific shape of the current collector, and then the waste area on the current collector is cut off along the edges of the coating area and the tab area in a laser cutting mode, so that the pole piece with the specific shape is obtained. The full-digital path programming is supported by the laser cutting, and the current collector is cut by adopting a laser cutting mode, so that the transformation time can be greatly shortened, the method is well suitable for cutting coating areas with different specifications and shapes, and is particularly suitable for manufacturing special-shaped pole pieces, and the preparation method of the pole pieces is a process route with flexibility characteristics and strong universality for manufacturing the pole pieces, and is free from the problem that the process flow is abnormal due to the fact that the shape specificity is large. In one embodiment, the laser cutting is performed by using a pulse laser with a pulse width of 50 fs-50 ps. Therefore, the heat overflow of the laser is reduced while the pulse laser can rapidly cut the current collector, so that the area of a heat affected zone of the active material layer is increased. In one embodiment, the laser power of the laser cutting is 50w to 300w. The heat affected zone area of the active material layer can be reduced as much as possible under the condition that the laser effectively cuts off the current collector by controlling the laser power. In an embodiment, the number of cutting turns of the laser cutting is 5-200. In order to ensure that the current collector is cut off, the number of cutting turns during laser cutting can be increased to connect all etched through holes ablated by laser on the current collector together, so that the tab area and the coating area are separated from the waste area. In an embodiment, a common edge is arranged between the tab area and the coating area, and the length of the common edge between the tab area and the coating area is 0.2-0.5 of the perimeter of the coating area. The common edge between the tab area and the coating area is a first common edge, and the longer the first common edge is, the less the area of the active material layer affected by laser is, and the smaller the area of the heat affected zone on the active material layer is. In addition, the length of the common edge between the tab area and the coating area is increased to be equal to the length of the tab area extending along the circumferential direction of the coating area, so that the tab area is increased, the internal resistance is reduced, the heat dissipation capacity is improved, and the current density distribution uniformity is improved. In one embodiment, the active material layer comprises a nickel cobalt manganese ternary material. The area of the heat affected zone of the active material layer can be reduced by providing the tab region adjacent to the coating region. In one embodiment, the thickness of the current collector is 4 μm to 15 μm. The mechanical strength of the current collector and the difficulty of laser cutting of the current collector can be effectively controlled by controlling the thickness of the current collector. In one embodiment, the thickness of the pole piece is 50-200 μm. The energy density of the battery can be controlled by controlling the thickness of the pole piece. In one embodiment, the method of making the pole piece further in