Synergistic enhancement of electrochemical performance of electrospun TiC/C hybrid nanofibers for supercapacitor application

Isotropically conductive TiC/C hybrid nanofibers (TCCNFs) have been prepared by electrospinning for supercapacitor application for the first time. By changing the atmosphere of stabilization process, the TCCNFs with different TiC contents were successfully synthesized with uniform morphology and average diameter of about 100 nm. The TCCNFs stabilized in Ar contain much more TiC than those stabilized in air. The specific capacitance of the TCCNFs stabilized in Ar and air were measured to be 77.8 F g(-1) and 130.0 F g(-1) at the current density of 0.1 A g(-1), respectively, which were much higher than the pure TiC nanoparticles and reported carbon materials with similar specific surface area. The charge storage mechanisms were discussed by analyzing the capacitive and diffusion-controlled contributions to the total capacitance. Reversible valance change of Ti atoms was observed during charge/discharge process, indicative of the occurrence of pseudoreaction. The experimental results support that the higher specific capacitance of the TCCNFs may be caused by a synergistic enhancing effect between TiC and carbon. The capacitance retention reaches 98.9% and 93.0% for the TCCNFs stabilized in Ar and air after 25 000 cycles, respectively, showing excellent stability. The present work provides a novel conductive electrode material for supercapacitors with possible pseudocapacitance, worthy of further investigation. (C) 2015 Elsevier Ltd. All rights reserved.