Polyaniline–V2O5 hybrid materials have been prepared by an oxidative intercalation reaction and the factors that affect their electrochemical discharge–charge performance have been investigated. The first discharge capacity of a sample produced from a nominal molar ratio of aniline: V2O5=3 (V2O5–(AN)3.0) is higher than that of a sample prepared from the lower ratio of aniline: V2O5=0.5 (V2O5–(AN)0.5). The V2O5–(AN)0.5 sample also shows better reversibility. Samples have been post-treated at different temperatures in air or oxygen. Post-treatment improves the electrochemical performance of V2O5–(AN)0.5 but degrades both the capacity and reversibility of V2O5–(AN)3.0. A V2O5–(AN)0.5 sample post-treated at 70°C in air exhibits the best discharge–charge characteristics.