Preparation method for mixture of nano silicon particles coated with silicon monoxide net-shaped structure and graphene lithium battery negative electrode material

Abstract

The invention provides a preparation method for a mixture of nano silicon particles coated with a silicon monoxide net-shaped structure and a graphene lithium battery negative electrode material. The preparation method comprises the following steps: (1) mixing a silicon compound with graphene to prepare a soluble mixture solution; (2) preparing the silicon compound and the graphene in the soluble mixture solution into nano particles; adding the nano particles into a cavity of microwave hot cracking equipment; and (3) controlling the oxygen partial pressure in the cavity to be 5-10000ppm and controlling the temperature to be 200-500 DEG C; reacting for 10-300 seconds and collecting powder in the microwave hot cracking cavity; and drying to obtain the mixture. According to the method, the process is simple; the nano silicon particles and the nano graphene particles in the prepared mixture of the nano silicon particles coated with the silicon monoxide net-shaped structure and the graphene lithium battery negative electrode material have good dispersibility and high purity.

Description

technical field [0001] The invention relates to the production field of battery electrode materials, in particular to a method for preparing a mixture of nano-silicon particles coated with a silicon monoxide network structure and a graphene lithium battery negative electrode material. Background technique [0002] With the depletion of non-renewable energy sources such as fossil fuels, people are increasingly demanding new types of renewable clean energy and energy storage and conversion technologies. Lithium-ion batteries have the advantages of high energy density, long cycle life, and no memory effect. They have been widely used in portable electronic devices such as mobile phones and notebook computers, and are expected to be used in electric vehicles, new energy storage and other fields. However, the theoretical specific capacity of graphite-based carbon anode materials for commercial application is only 372 mAh / g, which limits the further improvement of the energy dens...

AI Technical Summary

Problems solved by technology

Although this method can improve the cycle stability of silicon anode materials to a certain extent, this method also has many disadvantages: (1) when silicon is pulverized by ball milling, impurities are easily mixed into the solution, which affects the purity of nanoparticles; (2) Hydrogen treatment is easy to cause uneven reduction due to powder coalescence; (3) Hydrofluoric acid solution is easy to cause injury to operators, and acid discharge will cause environmental pollution; (4) Due to the nano Aggregation will occur between silicon particles, therefore, in the process of mixing the solution containing nano-silicon particles coated with silicon monoxide network structure and the graphene solution, it is impossible to ensure that the nano-silicon particles coated with silicon monoxide network structure and graphite Uniform distribution of ene particles; (5) complex process