Anode material of silicon-graphene battery and preparation method thereof, and lithium battery

Abstract

The present invention provides an anode material of a silicon-graphene battery and a preparation method thereof, and a lithium battery. The preparation method comprises the steps of: adopting metal cations to assist in etching of a silicon wafer to obtain a silicon nanowire array; and coating graphene on the surface of a silicon nanowire by adopting a chemical vapor deposition method to obtain a graphene-coated silicon nanowire. By adopting a method of assistant etching by employing metal cations, a large number of oxidation active sites are formed on the surface of the Si nanowire, the inconvenience is avoided that graphene is grown after an oxide layer needs to be formed in the traditional Si material, a graphene coating structure is achieved by adopting the CVD, a methane cracking source is attached to the surface of the Si nanowire through gas diffusion and transportation, and a uniform coating structure is easier to form; the charge-discharge stress release of the prepared batteryanode material is superior to that of the traditional carbon material, and the stability of the one-dimensional structure in the charge-discharge process is improved. The lithium battery has higher lithium storage capacity and stable cycle characteristics, provides a new choice for developing a high-performance lithium battery, and has a good application prospect.

Description

technical field [0001] The disclosure belongs to the technical field of new energy materials, and relates to a silicon-graphene battery negative electrode material, a preparation method thereof, and a lithium battery. Background technique [0002] With the development of modern society, energy conversion and storage is one of the major challenges that must be faced. Lithium-ion batteries have the advantages of high energy density and environmental friendliness, and are the mainstream technology in the field of energy storage today. In lithium-ion batteries, the electrode active material is the key to determine its performance. The traditional battery system based on carbon anode materials is already close to the limit of theoretical capacity (372mAh / g), which cannot meet the requirements of new technologies represented by electric vehicles for high-performance lithium-ion batteries. Ion batteries present an urgent need. Silicon (Si, Silicon)-based anode materials have a hi...

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Problems solved by technology

However, structural nanonization also increases the amount of SEI, leading to a larger irreversible capacity loss

On the other hand, as a semiconductor material, Si has weaker electron conductivity than metals. High battery internal resistance will reduce the working output voltage and increase energy loss, which will affect the improvement of its capacity.

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