Dual Cation- and Anion-Based Redox Process in Lithium Titanium Oxysulfide Thin Film Cathodes for All-Solid-State Lithium-Ion Batteries.

A dual redox process involving Ti/Ti cation species and S/(S) anion species is highlighted in oxygenated lithium titanium sulfide thin film electrodes during lithium (de)insertion, leading to a high specific capacity. These cathodes for all-solid-state lithium-ion microbatteries are synthesized by sputtering of LiTiS targets prepared by different means. The limited oxygenation of the films that is induced during the sputtering process favors the occurrence of the S/(S) redox process at the expense of the Ti/Ti one during the battery operation, and influences its voltage profile.

Thorough characterization of sputtered CuO thin films used as conversion material electrodes for lithium batteries.

CuO thin films were prepared by radio frequency magnetron sputtering using a copper target in a (Ar + O2) reactive mixture. Different sputtering parameters were varied including oxygen flow rate, total pressure, target-substrate distance, substrate temperature and target orientation. As expected, the thin film chemical composition is strongly dependent on the oxygen flow rate.