High-rate V2O5-based Li-ion thin film polymer cell with outstanding long-term cyclability

An innovative V2O5 based multiphase electrode/electrolyte composite is prepared by a fast, versatile and easily scalable UV-induced free-radical photo-polymerisation technique and its electrochemical properties are thoroughly investigated. The compact configuration consists of a highly conducting methacrylic-based polymer electrolyte directly formed over a r.f. sputtered V2O5 thin film positive electrode. All-solid state thin-film Li and Li-ion cells are assembled by simply contacting the polymeric side of the compact composite with either lithium or graphite as anode in the respective cases, and long-term galvanostatic charge/discharge cycling studies are performed. The FESEM analysis after long-term cycling confirms the active role of the polymer electrolyte in stabilizing the cycling behaviour which, in turn, prolonged the life span of the cell operation. Such an assembly is one of the finest example in which a solid Li-ion polymer cell is cycled at a rate as high as 5C at ambient temperature. The results of the electrochemical and morphological studies confirm that the methodology presented here is versatile and economical to produce a well-functioning and easily up scalable Li-ion thin film battery.