In situ synthesis of carbon fiber-supported SiOx as anode materials for lithium ion batteries

Abstract

The carbon fiber-supported SiO_x (CF–SiO_x) composites are in situ fabricated using a facile two-step method and evaluated as anodes for lithium-ion batteries (LIBs). The CF–SiO_x anodes exhibit a reversible capacity of 1100 mA h g⁻¹ at 50 mA g⁻¹ after a high current charge–discharge cycling test with a capacity retention of 80% (compared with the first 5 cycles). This superior performance of the CF–SiO_x are due to the modification of SiO_x with the profiled carbon fibers, which effectively construct a continuous conducting network and thus enhance the electrochemical activity of SiO_x. The profiled carbon fibers have numerous surface grooves to provide high contact area for rapid lithium-ion transport and enough inter-fiber space for the accommodation of large SiO_x volume changes on lithium insertion and extraction.