Covalent binding of holey Si-SiC layer on graphene aerogel with enhanced lithium storage kinetics and capability

Silicon/graphene hybrid materials are promising high-capacity anodes toward lithium storage. However, silicon guests are often physically combined with graphene host, and the free space is not sufficient and interconnected, which is not beneficial for the structural integrity and electrolyte permeation. Herein, we develop a gel-enabled route for chemically binding silicon-based materials on graphene matrices with continuous skeleton and inter-connected porosity. Specifically, holey Si-SiC layers are closely plastered and covalently bound on graphene (G) aemgel through magnesiothermically co-reducing an interpenetrated gel consisting of SiO2 and graphene oxide (GO) units. The gel-derived framework structure and holey coating layer together with strong covalent binding enable the Si-SiC/G framework anode to exhibit good cycling life (1060 mA h g(-1) after 100 cycles at 0.5 A g(-1)) and high rate capability (632 and 441 mA h g(-1) at 5 and 10 A g(-1), respectively).