Method for preparing porous silicon/carbon/nano metal composite negative electrode material by plasma activated cutting of silicon waste

Abstract

The invention relates to a method for preparing a porous silicon / carbon / nano metal composite negative electrode material by plasma activated cutting of silicon waste, which belongs to the technical field of new energy materials and electrochemistry. The method comprises the following steps that the diamond wire cutting silicon waste and carbon source powder are uniformly mixed and plasma activation treatment is carried out; silicon and carbon are gasified, condensed and recrystallized to obtain a nano-silicon / carbon composite material, impurities in silicon waste can be removed through plasmaactivation treatment, nanocrystallization of silicon and carbon is achieved, and the silicon / carbon composite material is subjected to nano metal particle compounding to prepare the porous silicon / carbon / nano metal composite material. According to the porous silicon / carbon / nano metal composite negative electrode material prepared by the method, the transmission distance of lithium ions and electrons can be shortened, the overall conductivity and structural integrity of the electrode material are improved, and the problems of huge volume change and low rate capability in a lithium de-intercalation and intercalation process are effectively solved.

Description

technical field [0001] The invention relates to a method for preparing a porous silicon / carbon / nano-metal composite negative electrode material by cutting silicon waste through plasma activation, and belongs to the technical fields of new energy materials and electrochemistry. Background technique [0002] In the lithium-ion battery structure, the anode material is a very important component, which directly determines the quality and application of the lithium-ion battery. So far, lithium-ion battery anode materials mainly include carbon materials, lithium alloys (lithium-silicon alloys, lithium-tin alloys, etc.), transition metal oxides (TiO 2 , SnO 2 etc.), nitrides. Because graphite materials have good cycle stability, excellent electrical conductivity, and their layered structure has a good space for intercalation of lithium, the volume change in the process of intercalation and deintercalation of lithium is within an acceptable range. Graphite negative electrode mater...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims at the problems of high cost of lithium battery silicon negative electrode in the prior art, huge volume change during the cycle of silicon material, low intrinsic conductivity, and difficult recycling of silicon waste cut by diamond wire in the photovoltaic industry, and provides a method for preparing porous silicon waste by plasma activation cutting The method of silicon / carbon / nano-metal composite negative electrode material is to mix the diamond wire cut silicon waste with carbon source powder and undergo plasma activation treatment, silicon and carbon gasification, condensation and recrystallization to obtain nano-silicon / carbon composite material, plasma activation treatment can Remove impurities in silicon waste and realize nanometerization of silicon and carbon, and compound silicon / carbon composite materials with nano-metal particles to prepare porous silicon / carbon / nano-metal composite materials

The present invention adopts the combined treatment method of plasma activation composite-nano-metal particle composite to prepare cutting silicon waste into a high-performance negative electrode material for lithium-ion batteries, that is, a porous silicon / carbon / nano-metal composite negative electrode, which can shorten the transmission distance of lithium ions and electrons , improve the overall conductivity and structural integrity of the electrode material, and effectively solve the problems of huge volume change and low rate performance during the lithium-deintercalation process

Images