Synthesis of SiOx/C composite with dual interface as Li-ion battery anode material

A dual interface SiOx/C composite is prepared through a novel, facial, one-step route by redox reaction of organic carbon with silica precursor, using tetraethyl orthosilicate (TEOS) and sucrose as raw material, in which sucrose acts as both a reductant and coated carbon. HRTEM indicates that the composite has a dual interface structure with carbon coating layer and intermediate layer. Crystalline Si approximately 3 nm–20 nm in size is dispersed in amorphous silicon oxide matrix. The SiOx/C is utilized in LIB as anode material and exhibits a high reversible specific capacity of 755 mA h g−1 after 300 cycles at 100 mA g−1 with capacity retention about 91%. Such outstanding cycling stability can be ascribed to the intermediate layer and carbon scaffold, which serve as a buffering to relieve volume change of produced Si upon cycles.