V₂O₅正極を用いた全固体薄膜リチウムイオン電池の作製とその評価

抄録

Lithium ion batteries are widely used in various kinds of portable devices because of their high voltage and energy density. Recently all-solid lithium ion batteries have been studied to solve the problems of liquid electrolyte. In order to fabricate all-solid thin-film battery composed of V₂O₅ cathode, we fabricated V₂O₅ thin film on Pt/Ti/glass substrate by RF-magnetron sputtering and evaluated electrochemical properties of V₂O₅. As a result, the specific capacity of V₂O₅ with thickness of 0.5 μm is higher than 100 mAh/g at 1C rate and the cycle performance of V₂O₅ with thickness of 2.5 μm kept more than 90% capacity over 30cycles. Therefore we confirmed that V₂O₅ works well as cathode material of lithium ion battery. Subsequently we fabricated all-solid thin-film battery composed of V₂O₅ cathode and Si anode and LiPON electrolyte. It worked as thin-film battery and the capacity was about 50 nAh / (cm²∙μm) over 100 cycles.