Silicon-carbon negative electrode material and preparation method thereof

Abstract

The invention discloses a silicon-carbon composite negative electrode material and a preparation method thereof. The silicon-carbon negative electrode material comprises a nano-silicon material whichis prepared from nano-silicon and a conductive polymer material and is coated with a conductive carbon film on the surface, and the nano silicon material coated with the conductive carbon film is uniformly distributedin the spherical graphite, on the surface of the spherical graphite and on the surface of the graphene to form a nano silicon / graphite / graphene structure, and two layers of organic carbon sources are uniformly coatedon the nano silicon / graphite / graphene structure to obtain the silicon-carbon negative electrode material. The conductive polymer material and two layers of organic carbon sources are coated on the surface of the nano silicon, so that the conductivity of the silicon is enhanced, and the expansion of the silicon is inhibited; aslurry is subjected to drying and twiceroasting in a short time through three times of spray drying, so that the silicon-carbon negative electrode material which is relatively good in silicon dispersion effect and is uniformly coated withorganic pyrolytic carbon is obtained; the preparation method of the silicon-carbon composite negative electrode material is simple, environment-friendly, rich in used raw materials, low in equipment cost and suitable for industrial production and application.

Description

technical field

[0001] The invention relates to the technical field of electrochemistry and lithium-ion battery negative electrode materials, in particular to a silicon-carbon negative electrode material and a preparation method thereof. Background technique

[0002] In recent years, lithium-ion batteries have been widely used in cameras, power tools, computers, mobile phones, power batteries and energy storage due to their advantages such as high energy density, high working voltage, and long life. However, with the continuous development of society, especially today's rapid development of the electric vehicle industry, the demand for high-energy-density lithium-ion batteries is imminent, so the development of high-capacity lithium-ion battery anode materials is also particularly important.

[0003] At present, the anode materials for commercial lithium-ion batteries are mainly graphite materials, and their theoretical specific capacity is only 372mAh / g, which cannot meet t...

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