Silicon-Carbon nanofiber composite film for supercapacitor applications

A free-standing silicon-carbon nanofiber composite film was synthesized, and the film was investigated for supercapacitor applications. High specific capacitance of 206F/g in the three-electrode system and 242F/g in the two-electrode system at the current density of 1 A/g with energy density of 21.6 Wh kg−1 and the corresponding power density of 401 W kg−1 are obtained. Specific capacitance retention of 94.6 % and Coulombic efficiency of 87.8 % are also demonstrated after 5,000 cycles. The combination of carbon nanofiber as a support and silicon as an active material finally provide excellent supercapacitor performance.