Carbon Uniformly Distributed SiOx/C Composite with Excellent Structure Stability for High Performance Lithium-Ion Batteries.

Silicon oxides (SiOx, 0<x<2) has been considered as one of the most promising candidate materials for high specific energy anode materials and attracted extensive attention. However, there are still some shortcomings within SiOx that extremely limit its promotion in industry, especially the large volume expansion and poor conductivity. Reasonable design of silicon oxides (SiOx) electrode material is very important to improve its energy storage performance. Here, we fabricated a novel porous SiOx/C nanohybrids based on the facile sol-gel method followed by pyrolysis, in which carbon and SiOx not only exhibited uniform distribution at the nanoscale, the stability of SiOx/C network can also be easily adjusted via controlling the hydrolysis and condensation rate of precursors in situ. Thanks to the excellent electrical conductivity and structural stability of carbon, uniform distribution of SiOx and carbon at the nanoscale, as well as the porous structure. The SiOx/C(50) electrode, with the most appropriate carbon content, delivered a high lithium storage capacity and excellent cyclability. Specifically, a reversible capacity of 808 mA h g -1 can be achieved at 100 mA g -1 , retaining 666 mA h g -1 after 100 cycles. And the reversible capacity still retained ∼550 mAh g -1 after 1200 cycles at a current density of 0.5 A g -1 .