Electrically exfoliated graphene silicon carbon composite material as well as preparation method and application thereof

Abstract

The invention relates to an electrically exfoliated graphene silicon carbon composite material. A preparation method comprises the following steps: mixing electrically exfoliated graphene, a silicon-based material and a saccharide material according to a certain ratio, and then carrying out ball milling; carrying out spray drying granulation on the ball-milled product; and carrying out high-temperature calcination on the spray-dried product in an inert atmosphere to obtain a final product. The electrically exfoliated graphene silicon carbon composite material is prepared by the preparation method. The invention also discloses an application of the electrically exfoliated graphene silicon carbon composite material in a lithium ion battery. The electrically exfoliated graphene silicon-carbon composite material has the beneficial effects that the electrically exfoliated graphene is compounded with the silicon-based material and the saccharide material to synthesize the electrically exfoliated graphene silicon-carbon composite material with excellent cycle performance, that is, the electrically exfoliated graphene silicon-carbon composite material contains the electrically exfoliated graphene, and the content of the electrically exfoliated graphene can reach 20%; and the adopted method is high in efficiency, the production process is simple and easy to control, and large-scale production is easy.

Description

technical field [0001] The invention relates to the field of lithium-ion batteries, in particular to an electrically exfoliated graphene-silicon-carbon composite material and a preparation method and application thereof. Background technique [0002] With the popularization of electronic devices and electric vehicles, people's demand for energy density of lithium-ion batteries is getting higher and higher, which urgently requires scientists to explore new anode materials with high energy / power capacity to replace the current mainstream graphite anode. [0003] Silicon (Si) is considered to be one of the most promising high-capacity anode substitutes for graphite anodes for the following reasons: [0004] 1) Silicon has 4200mAhg ～1 gravimetric capacity (lithiated to Li 4.4 Si); [0005] 2) Lithium ion intercalation / deintercalation potential is low (less than 0.5VvsLi / Li + ), it is not easy to precipitate lithium dendrites; [0006] 3) Silicon is the second most abundant ...

AI Technical Summary

Problems solved by technology

[0009] 2) Destruction of the electron-ion transport pathway;

[0010] 3) Instability of the solid electrolyte interface (SEI);

[0011] In addition, the diffusion coefficient of silicon in lithium (10 ～14 ~10 ～13 cm 2 the s ～1 ) and intrinsic conductivity (10 ～5 ~10 ～ 3 Scm ～1 ) is low, all these factors limit the cycle life and rate performance of silicon anodes

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