Phosphate-doping silicon carbon negative electrode material for lithium ion battery and preparation method of phosphate-doping silicon carbon negative electrode material

Abstract

The invention discloses a phosphate-doping silicon carbon negative electrode material for a lithium ion battery. The phosphate-doping silicon carbon negative electrode material is formed by sinteringa phosphate-doping nanosilicon material, graphite and an organic carbon source after spray granulation. The invention also proposes a preparation method of the phosphate-doping silicon carbon negativeelectrode material for the lithium ion battery. The preparation method comprises the steps of uniformly dispersing the nanosilicon material in a phosphoric acid solution, and performing spraying anddrying to obtain the phosphate-doping nanosilicon material; performing primary sintering on the phosphate-doping nanosilicon material; and uniformly dispersing the phosphate-doping nanosilicon material subjected to primary sintering in water, adding the graphite and the organic carbon source, and performing spraying, drying and secondary sintering after complete dispersion. The preparation methodof the phosphate-doping silicon carbon negative electrode material for the lithium ion battery, proposed by the invention, has the advantages of simple process, low cost and convenient subsequent processing mode and is convenient to operate, the raw material is natural and available, mass production is easy, and the obtained negative electrode material is high in electron conductivity and small involume expansion.

Description

technical field [0001] The invention relates to the technical field of lithium-ion battery materials, in particular to a phosphorus-doped silicon-carbon negative electrode material for lithium-ion batteries and a preparation method thereof. Background technique [0002] In recent years, with the continuous expansion of the application of lithium-ion batteries in high-power equipment such as electric tools, electric / hybrid vehicles, and energy storage power stations, traditional graphite negative electrodes (372mAh / g) have been difficult to meet human needs for high-energy-density batteries. Therefore, finding a next-generation lithium-ion battery anode material that can replace graphite has become one of the current research hotspots in lithium-ion batteries. The theoretical specific capacity of silicon material is 4200mAh / g, which is rich in resources and will not co-intercalate with the electrolyte. At the same time, the lithium intercalation potential is higher and safer....

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Problems solved by technology

However, these methods all use carbon materials or conductive polymers to improve the electronic conductivity of silicon-based materials, and do not improve the intrinsic electronic conductivity of silicon materials.

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