2004 年 72 巻 4 号 p. 261-265
Vanadium oxide films were deposited by r.f. magnetron sputtering technique on SUS 304 stainless steel substrates in Ar + O2 atmosphere using V2O5 target. The films obtained were characterized by X-ray diffractometry and scanning electron microscopy. The XRD and SEM observations show that the crystallographic orientation and surface morphology of the vanadium oxide films are changed with film thickness. For the thin film with thickness of 450 nm the V2O5 phase with the ab plane parallel to the substrate is formed, resulting in a highly smooth surface, while for thicker films with thickness of 1.0~4.0μm the V2O5 phase with the ab plane perpendicu1ar to the substrate is formed, giving a considerably rugged surface. The vanadium oxide films undergo a reversible lithium intercalation and deintercalation process, and the thicker film (4.0μm) showed more distinct stepwise discharge profile than the thin film (0.45 μm). The kinetics of intercalation process of lithium into the V2O5 film was studied using an electrochemical transient technique, deducing kinetic parameters such as chemical and lithium component diffusion coefficients and activation energy for lithium diffusion.
