▎ 摘　　要

Large volume changes, poor conductivity, and unstable solid electrolyte interphase (SEI) are the main problems that hinder the development of Si electrodes. In this paper, we prepared graphene and citric acid as the carbon sources. Si@amorphous carbon/graphene (Si@C/G) composites were obtained by high-temperature calcination and self-assembly of electrostatic attraction. The electrostatic attraction of amino and carboxyl groups not only inhibited the agglomeration of Si particles and the accumulation of graphene sheets, but also helped encapsulate the carbon-coated nano-Si (Si@C) into graphene. Therefore, the volume expansion and collapse of Si were suppressed during charge and discharge. Meanwhile, graphene and amorphous carbon prevented Si from being directly exposed to the electrolyte. Furthermore, the three-dimensional (3D) conductive network composed of amorphous carbon and graphene improved the conductivity of Si-based electrodes. Compared with Si electrodes, Si@C/G electrodes showed good electrochemical performance.