화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.152, No.1, A236-A241, 2005
Structural and electrochemical properties of omega-LixV2O5 (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 &LE; x &LE; 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.