Efficient preparation of 2D-Si@C composite by gas-phase approach for lithium-ion storage

Abstract

Graphite has long served as a mainstream anode material for lithium-ion batteries (LIBs), having approached its theoretical capacity limit. Silicon (Si)-based materials have garnered considerable attention owing to their notable Li-ion storage capacity and similar working platform with graphite. However, an inherent challenge lies in the substantial volumetric changes that Si-based materials undergo during the Li-ion insertion and extraction processes, resulting in a pronounced reduction in their capacity and stability. Herein, a pioneering two-dimensional Si-based material (2D-Si) is introduced and successfully synthesized through a gas-assisted method in this work. A designed Si-based composite (2D-Si@C), exhibiting exceptional electrochemical characteristics, is obtained through a devised post-processing procedure. When employed as an electrode, the as-prepared 2D-Si@C composite manifests an excellent Li-ion storage capacity, rate performance, and cycling stability in comparison to conventional bulk Si. In the meantime, an in-depth investigation into the impact of gas-phase reactions at different temperatures on the electrochemical performance has also been conducted to elucidate the structural advantages of the material.