Preparation method of multiple composite anode material of lithium ion battery

Abstract

The invention discloses a preparation method of a multiple composite anode material of a lithium ion battery. The preparation method comprises the following steps of: (1) treating silicon, silicon monoxide and cane sugar by methods such as ball milling and carbonization to obtain a primary sample with a silicon / silicon monoxide / carbon multiple composite structure; (2) dispersing the primary sample obtained in the step (1) in the mixed solution of ethyl orthosilicate and ethanol and adding excessive distilled water so that the ethyl orthosilicate is completely hydrolyzed into silicon dioxide, and drying; performing treatments such as ball milling and carbonization on the sample obtained after drying and polyvinyl chloride to obtain the silicon / silicon monoxide / carbon / silicon dioxide / carbon multiple composite anode material. The composite cathode material prepared by the method provided by the invention is spherically granular, even in particle size distribution and high in electronic conductivity; and the cathode material with such a composite structure is capable of improving the electrochemical properties of a silicon-based material.

Description

technical field [0001] The invention relates to a preparation method of a multiple composite negative electrode material of a lithium ion battery. Background technique [0002] Lithium-ion battery is a new type of rechargeable battery with high specific energy, long service life, clean and pollution-free. It has been widely used in various portable electronic devices, electric vehicles, large energy storage base stations and other fields. In the structure of lithium-ion batteries, the positive and negative electrode materials are the key substances that determine the energy storage, service life, price and other factors of lithium-ion batteries. However, since the commercialization of lithium-ion batteries, the positive electrode materials have been continuously introduced, while the negative electrode materials have been using graphite materials, which hinders the further improvement of the energy density of lithium-ion batteries, making the current lithium-ion batteries un...

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Problems solved by technology

[0004] The existing preparation methods of silicon-based negative electrode materials mainly use carbon sources (such as sucrose, pitch, etc.) to compound silicon with silicon under ball milling, and then use carbonization and sintering to obtain silicon-carbon composite materials. Simultaneously with the simplification of the process, the obtained silicon-carbon composite material has poor cycle stability due to its simple structure and looseness, which is not conducive to buffering the volume expansion of silicon in the case of high lithium intercalation. suitable for commercial applications

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