Journal of Power Sources, Vol.146, No.1-2, 327-330, 2005
Electrochemical and Structural properties of V2O5 thin films prepared by DC sputtering
Vanadium pentoxide thin films have been prepared by reactive DC magnetron sputtering from a vanadium metal target without annealing posttreatment. XRD, Raman and electrochemical experiments on 800 nm thin films show a high crystallinity of the deposits. Chronopotentiometric measurements performed in the two voltage range 3.8-2.8 and 3.8-2.15 V have demonstrated the promoting effect of the h 0 0 preferred orientation of V2O5 films in terms of polarization, kinetics and rate capability. The same reproducible deposition method is successfully applied to get films thicker than 1 mu m in order to optimize the specific capacity. Effective high specific capacities can be then obtained with films 2.4 mu m thick tested at high constant current density (100 mu A cm(-2)): a stable capacity of 75 mu Ah cm(-2) is available over 100 cycles in the 3.8-2.8 V potential range and 130 mu Ah cm(-2) are still recovered in the range 3.8-2.15 V. These results indicate a promising cycling behaviour can be expected with thick films exhibiting a preferred orientation corresponding to V2O5 planes perpendicular to the substrate. (c) 2005 Elsevier B.V. All rights reserved.