Cobalt-embedded porous carbon derived from a facile in-situ strategy enables improved lithium storage performance of silicon anode

Abstract

It is still one of the most critical challenges to overcome the problems caused by the volume change of the silicon (Si) in improvement of the performance of the Si-based anodes. In addition, for a promising Si-based anode material, obtaining a simple preparation route is as important as improving its performance. Nevertheless, most of the reported Si-based anodes lack simple preparation methods in spite of high performance. Herein, the lithium storage performance of the Si is significantly improved by constructing a Si/C/Co composite that consisting of Si nanoparticles embedded within CoO nanoparticles-decorated porous carbon matrix and hence the problems caused by the volume change of the Si are efficiently mitigated during cycle. Remarkably, the preparing process of the Si/C/Co composite just contains very simple two steps of grinding and calcination. By comparing the performance of the optimized Si/C/Co (Si/C/Co-212) to a series of control samples, we confirm that the synergistic effects of the porous carbon matrix and the metallic Co nanoparticles that are in-situ derived from the electrochemical reduction of CoO component contribute to improved structural stability, high conductivity and fast kinetics of the Si/C/Co-212 electrode during the cycle. As a result, the Si/C/Co-212 manifests outstanding performance as lithium-ion battery anodes. The simple preparation process and the remarkable performance enable Si/C/Co-212 to have promising prospect in lithium-ion battery application.