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

Abstract

Silicon oxide (SiO_x) 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 SiO_x nanowires (pC–SiO_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–SiO_x NWs and formation of a stable solid-electrolyte interphase (SEI) film on the external surface of pC–SiO_x 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.