V2O3/C nanocomposites with interface defects for enhanced intercalation pseudocapacitance

Abstract

V2O3 nanoparticles highly dispersed in amorphous carbon composites (VO-C) were successfully synthesized by the calcination of (NH4)2V3O8/C precursor, which was fabricated through the hydrothermal reaction using commercial NH4VO3 and glucose as raw materials. The release of gaseous byproduct during the formation of V2O3 and amorphous carbon resulted in the formation of highly dispersed oxide nanoparticles dispersed in porous carbon matrix. The composites exhibited a high specific intercalation pseudocapacitance of 458.6 F g−1 at 0.5 A g−1 with a retention of 86% after 1000 cycles in aqueous electrolyte. Such good electrochemical properties is attributed to the high diffusion coefficient and promoted electron transfer of the composites possibly as a result of surface modification of V2O3 nanoparticles. In addition, highly porous carbon network with homogeneously dispersed V2O3 permits efficient intercalation reaction with much enhanced stability of V2O3. Flexible asymmetric supercapacitors using synthesized VO-C and active carbon electrodes were assembled and demonstrated excellent electrical energy storage performance.