Method for preparing silicon carbon composite material by taking silicate glass as raw material, product thereof and application

Abstract

The invention discloses a method for preparing a silicon carbon composite material by taking silicate glass as a raw material, a product thereof and application. The method comprises the following steps: performing wet ball milling on glass powder and a carbon material to obtain a uniformly mixed product of the glass and the carbon material, uniformly mixing the uniformly mixed product, magnesiumpowder and molten salt, pressing into an ingot, performing magnesium thermal reaction, and performing acid-washing treatment on the reaction product to obtain the carbon and silicon composite materials with different structures. According to the method, the steps are simple and practical, the raw material source is wide, most importantly, the magnesium thermal reaction is conducted after the mixture is made into the ingot, so that the ramming density of the silicon carbon negative electrode material is greatly increased and the volume specific capacity of the negative electrode material is increased; meanwhile, the electronic conductivity of the silicon carbon composite material formed by compounding the negative electrode material and a graphited carbon material is effectively improved, and the compatibility of the silicon based material and electrolyte is improved, so that the circulating performance and the rate performance of the material are improved, and the material can be applied to a lithium ion battery negative electrode material with high power density and high energy density.

Description

technical field [0001] The invention belongs to the field of lithium-ion battery negative electrode materials, and more specifically relates to a method for preparing a silicon-carbon composite material using silicate glass as a raw material, its product and application. Background technique [0002] The energy crisis and environmental problems are becoming increasingly prominent in today's society, and new clean energy and energy storage have become a hot research topic. Due to its high energy density, high power density, long life and environmental friendliness, lithium-ion batteries have broad application prospects in the fields of electric vehicles, large-scale energy storage devices, and distributed mobile power supplies. However, the mass specific capacity and energy density of lithium-ion batteries need to be further improved to meet the requirements of miniaturization of portable electronic products and their applications in aerospace, military, power grid peak regul...

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Problems solved by technology

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a method for preparing silicon-carbon composite materials using silicate glass as a raw material, its products and applications, the purpose of which is to combine waste silicate-based glass powder with The carbon material is mixed evenly by wet ball milling, then carbonized, then mixed with magnesium powder and molten salt, compacted into an ingot, and subjected to magnesium thermal reaction to obtain a silicon-carbon composite material. The preparation method is simple, the process is safe, and the cost is low. The obtained silicon-carbon composite material has high tap density and compaction density, and has good performance as a negative electrode material for lithium-ion batteries, thus solving the problem of harsh preparation conditions, high cost, complicated steps, Serious pollution and other problems, while the volume energy density and mass energy density of the silicon-carbon anode material prepared at the same time are low and cannot meet the application requirements of battery anode materials and other technical problems

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