Preparation method of silicon negative plate

Abstract

The invention provides a preparation method of a silicon negative plate. The preparation method of the silicon negative electrode plate comprises the following steps: obtaining a negative electrode plate, wherein the negative electrode plate is coated with negative electrode slurry comprising a silicon-based negative electrode material and a polymer adhesive; winding the negative plate by adopting a hollow roller to obtain a negative roll; the negative electrode roll is sealed through a coating film, so that a coating barrel is formed on the periphery of the negative electrode roll, and the length of the coating barrel is larger than that of the negative electrode roll; the negative electrode roll subjected to sealing treatment is subjected to sealing treatment through a sealing part, so that the two ends of the wrapping barrel are squeezed into the hollow roller, the sealing part penetrates through the hollow roller, and the wrapping films at the two ends of the wrapping barrel are clamped between the hollow roller and the sealing part; and carrying out staged heat treatment on the blocked negative electrode roll. According to the preparation method of the silicon negative electrode sheet, the bonding performance of the silicon-based negative electrode material can be realized, and the oxidation degree of the copper foil sheet can be reduced.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a preparation method of a silicon negative electrode sheet. Background technique [0002] Lithium batteries have the advantages of high working voltage and high energy density, and are widely used in large precision machinery, large power tools and digital products. However, due to the limitation of lithium battery anode materials, the energy density of lithium batteries cannot be further improved. And then found the replacement material of lithium battery negative electrode material - silicon, the theoretical specific capacity of silicon is as high as 4200mAh / g, and the reserves are abundant, but the silicon-based negative electrode material will be accompanied by a large volume change during the charging and discharging process, causing the silicon negative electrode The electrode material of the sheet falls off, and the expansion of the electrode material is accompanied by a...

AI Technical Summary

Problems solved by technology

[0002] Lithium batteries have the advantages of high working voltage and high energy density, and are widely used in large precision machinery, large electric tools, and digital products. However, due to the limitation of lithium battery negative electrode materials, the energy density of lithium batteries cannot be further improved. Furthermore, silicon was discovered as a replacement material for the negative electrode material of lithium batteries. The theoretical specific capacity of silicon is as high as 4200mAh / g, and the reserves are abundant. The electrode material of the sheet falls off, and the expansion of the electrode material is accompanied by a large safety hazard. In order to ensure the improvement of the energy density of the lithium battery and the safety of the lithium battery, that is, to reduce the expansion of the silicon-based negative electrode material, it is now generally used The binder with higher bonding strength adheres to the silicon-based negative electrode material to reduce the expansion degree of the silicon-based negative electrode material. The binder with higher bonding strength is generally a polymer adhesive, especially polyamide- The imide adhesive needs to be mixed and coated with the silicon-based negative electrode material and then treated at high temperature to make the monomer cross-linked and polymerized to form a network structure to realize the polymer adhesive on the silicon-based negative electrode material and foil. In the process of high-temperature treatment of the negative electrode sheet, it is easy to cause oxidation of the copper foil, which in turn affects the electrical properties of the negative electrode sheet

Images