Electrochemical behaviour of vanadium bronze Li6V5O5 cathode in a secondary lithium battery

A new vanadium oxide that is rich in lithium (Li6V5O15 has been prepared from Li2CO3 and V2O5 at 680°C for 24 h. The discharge behaviour of the bronze electrode is investigated in an Li/LiAsF6-PC/bronze battery at various current densities. The new material has good reversibility for lithium insertion; a high specific capacity (more than 340 Ah kg−1) is obtained at 0.2 mA cm−2 and a 1.0 V cutoff voltage. Given the good structural stability of the bronze with Li+ insertion, 160 cycles are achieved with the tentative battery. A.c. impedance data for the Li/Li6V5O15 cell reveal that the cathodic process is controlled mainly by Li+ diffusion in the bronze. The new bronze could be used for a low-voltage, rechargeable lithium battery.