Structural and electrochemical properties of omega-Li(x)V(2)O(5) (0.4 <= x <= 3) as rechargeable cathodic material for lithium batteries

The omega-LixV(2)O(5) phase (0.4 less than or equal to x less than or equal to 3) has been investigated as rechargeable cathodic material for lithium batteries. The interest in using the v phase as rechargeable electrode consists in the stability of its tetragonal structure (DeltaV/V < 1%) as the Li insertion-extraction proceeds. Lithium ions are found to be responsible for the ordering of the structure. AC impedance measurements have shown important kinetic limitations appear in the Li composition range 2.2 <= x <= 3, hindering the use of high current densities. However, at C/20 rate a remarkable and stable specific capacity of 310 mAh g(-1) is obtained over 30 cycles. Its cycling behavior in the 3.8/1.5 V voltage window has been shown to strongly depend on the C rate and temperature. At a higher rate (C/5), the capacity decline observed as galvanostatic cycling proceeds has been found to originate from a significant dissolution process of the vanadium oxide, leading to the presence of V(IV) and V(III) species in electrolyte. (C) 2004 The Electrochemical Society.