Self-sacrificed synthesis of carbon-coated SiOx nanowires for high capacity lithium ion battery anodes

Silicon oxide (SiOx) shows great potential for lithium ion battery (LIB) anodes due to its high capacity, environmental friendliness, low cost and high abundance. Herein, we used low-cost mesoporous silica spheres to synthesize core-shell structured porous carbon-coated SiOx nanowires (pCSiO(x) NWs) as a new LIB anode through a novel self-sacrificed method. The one-dimensional structure can accommodate large volume expansion without breaking. The porous carbon coating hinders the penetration of the electrolyte into pC-SiOx NWs and formation of a stable solid-electrolyte interphase (SEI) film on the external surface of pC-SiOx NWs. As a result, the composite shows excellent cycling stability with high reversible specific capacities of 1060 mA h g(-1) (100 cycles) and 623 mA h g(-1) (150 cycles) at current densities of 100 mA g(-1) and 500 mA g(-1), respectively. The proposed facile and scalable synthesis is highly competitive for large-scale applications in lithium storage devices/systems.