The polyaniline-V2O5 system:: improvement as insertion electrode in lithium batteries

Abstract

The application of a hybrid PAni-V2O5 cathode material in reversible lithium electrochemical cells is reported. We have studied the influence of synthesis conditions and subsequent treatments of the hybrid under oxygen in order to optimize its performance as a lithium-insertion cathode. The temperature and length of this treatment is a key parameter in determining the final specific charge of the cathode. The optimal material yielded a specific charge as high as 302 Ahkg-1 measured at low discharge rate (C/48) corresponding to the insertion of 2.72 lithium ions per formula unit (C6H4N)0.6V2O5-0.3H 2O). Higher scan rates of C/12 lead to specific capacities of 200 Ahkg-1. The thermal and electrochemical stability of the hybrid, especially in relation to the decomposition of the organic polymer and their effect on battery performance and cyclability are also discussed.