Study on the capacitance performance of Sn4+-doped V2O5

Sn⁴⁺-doped V₂O₅ cathode materials were prepared by a sol–gel method. The results showed that the modified cathode material was a mixture of V⁴⁺ and V⁵⁺. It was a kind of typical mesopore material with pores of 2–4 nm diameter. Symmetrical curves were obtained by cyclic voltammetry (CV) tests performed at different scanning rates and voltage ranges. In particular, the CV curve showed more obvious rectangle property and better redox properties when the scanning rate was 5 mV s^?1. At the current density of 200 mA g^?1, the maximum specific energy, specific power, and coulomb efficiency of the material were 27.25 mA h?g^?1, 494.87 W?kg^?1, and 97%, respectively. It was indicated that small amounts of Sn⁴⁺ doping would improve the surface morphology and electronic conductivity of V₂O₅. The Sn⁴⁺-doped V₂O₅ showed good capacitance characteristics.