High performance vanadium oxide thin film electrodes for rechargeable lithium batteries

摘要

Plasma Enhanced Chemical Vapor Deposition (PECVD) was used to prepare vanadium oxide thin films as cathodes for rechargeable lithium batteries. The reactants consisted of a high vapor pressure liquid source of vanadium (VOCl_3) and hydrogen and oxygen gas. Deposition parameters s uch as the flow rates of H-2, O_2 and VOCl_3, the substrate temperature and the Rf power were optimized, and high depositioin rate of 11 A/s was obtained. Vanadium oxide films with high discharge capacities of up to 408 mAh/g were prepared. The films also showed a superior cycling stability between 4 and 1.5 V at a C/0.2 rate for more than 4400 cycles. The films were amorphous up to a deposition temperature of 300 deg C, however, deposition on to substrates with textured surfaces facilitated the formation of crystalline films. We demonstrate that both the vanadium oxide material and the PECVD deosition method are very attractive for coonstructing thin-film rechargeable lithium batteries with high capacity and long-term cyclic stability.