Abstract
V4+-rich V2O5/carbon aerogel (V4+-V2O5/CA) composites were synthesized as electrode materials for supercapacitors via in-situ hydrolysis-condensation processing. Carbon aerogel (CA) promotes the deposition of amorphous vanadium oxide and catalyzes the crystallization of V4+-rich V2O5 nanosheets at much reduced temperature. With a uniform distribution of V2O5 nanosheets in CA, the special structure provides a large specific area and reactive sites. CA also synergistically improves the electrical conductivity and structural integrity. In addition, rich V4+ would enhance the intrinsic electrical conductivity of V2O5, promote ion diffusion and catalyze the electrochemical reactions. Consequently, V4+-V2O5/CA exhibits much enhanced specific capacitance (405 F g(-1) at 0.5 A g(-1)), high energy density (56 W h kg(-1) with a power density of 250 W kg(-1)) and long cycle life (96% capacitance retention after 40,000 cycles).