Preparation method of SiOx/C composite negative electrode material electrode for lithium-ion batteries

Abstract

The invention relates to a preparation method of a SiOx / C composite negative electrode material electrode for lithium-ion batteries, and belongs to the technical field of lithium-ion battery electrodes. In order to solve the problems of crushing, shedding and poor stability caused by the existing expansion, the invention provides a preparation method of a SiOx / C composite negative electrode material electrode for lithium-ion batteries. The preparation method comprises the steps of preparing SiOx slurry and carbon negative electrode slurry, wherein the SiOx slurry includes active SiOx, a conductive agent, a binder and epoxy resin, x is 0 or 1, the carbon negative electrode slurry includes a carbon negative electrode material, a conductive agent, a binder and epoxy resin; selecting a corresponding current collector, coating the SiOx slurry on the surface of the current collector to form a SiOx base film, and drying, wherein the porosity is 45%-75%; then coating the surface with the carbon negative electrode slurry, and drying to obtain the corresponding coated SiOx / C composite negative electrode material electrode. The preparation method has the effects of simple process, easy operation, high energy density, ability of being not easy to fall off and good cycle stability.

Description

technical field [0001] The invention relates to a lithium ion battery SiO x The preparation method of / C composite negative electrode material electrode belongs to the technical field of lithium battery electrodes. Background technique [0002] In recent years, with the rapid development of electronic technology and the emergence of large electric vehicles, higher requirements have been placed on the energy density, power density, safety and lifespan of lithium-ion batteries. In terms of energy density, it mainly depends on the reversible capacity of the electrode materials used in the battery and the voltage difference between the positive and negative electrodes. At present, there is relatively little room for improvement in cathode materials, and unlike cathode materials, there is a large selection space for available anode materials for lithium batteries. For example, silicon-based materials have received widespread attention in recent years, and the selection of silic...

AI Technical Summary

Problems solved by technology

For example, silicon-based materials have received widespread attention in recent years, and choosing silicon-based materials as negative electrodes can also improve safety better, but silicon-based material negative electrodes also face major problems in practical applications, such as During alloying, a huge volume expansion will result in self-powdering, which will cause the loss of electrical contact with the current collector, and damage the cycle stability and reversible capacity of the electrode.

[0003] In view of the above problems, in the prior art, when applying silicon-based materials in lithium battery negative electrodes, silicon-based materials are generally coated with graphite and other materials to make composite negative electrode materials, and then the composite materials and binders , The conductive agent is mixed and coated on the negative electrode current collector, but the processing cost is high and the process is complicated. At the same time, the powder will also fall off due to the expansion of the silicon-based material during use.

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