Three dimensional network Si–C composite coating constructed by porous skeletons as an integrated anode for lithium-ion batteries

Abstract

This paper reports a facile knife coating route to synthesize Cu-supported Si–C composite as an integrated anode for lithium-ion batteries. The composite displays a three dimensional (3D) network structure constructed by porous skeletons with Si nano-particles encapsulated in carbon matrix. The Cu-supported Si–C composite electrode demonstrates good capacity retention performance and rate performance. It delivers a high capacity of 1429 mA h g−1 at a current density of 1 A g−1 after 100 cycles and a capacity of 677 mA h g−1 at a high current density up to 20 A g−1. There are two facts responsible for its excellent electrochemical performance: (1) 3D network structure produced by volatilization of polymethylmethacrylate (PMMA) improves structure stability of the electrode; (2) abundant tunnels in skeletons made by volatilization of polyethylene glycol (PEG) increases diffusion of lithium-ions in the electrode.