CNRS, Universite de Bordeaux, ICMCB UPR 9048 and Bordeaux INP, Pessac, France, ST Microelectronics, 16 rue Pierre et Marie Curie, Tours, France, IPREM-ECP CNRS UMR 5234, Universite de Pau, 2 avenue Pierre Angot, Pau, France, CEA LETI, Minatec Campus, 17 rue des Martyrs, Grenoble, France, Universite Grenoble Alpes, Grenoble, France

A dual redox process involving Ti3+/Ti4+ cation species and S2-/(S2)2- 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 allsolid-state lithium-ion microbatteries are synthesized by sputtering of LiTiS2 targets prepared by different means. The limited oxygenation of the films that is induced during the sputtering process favors the occurrence of the S2-/(S2)2- redox process at the expense of the Ti3+/Ti4+ one during the battery operation, and influences its voltage profile. Finally, a perfect reversibility of both electrochemical processes is observed, whatever the initial film composition. All-solid-state lithium microbatteries using these amorphous lithiated titanium disulfide thin films and operated between 1.5 and 3.0 V/Li+/Li deliver a greater capacity (210-270 mAh g-1) than LiCoO2, with a perfect capacity retention (-0.0015% cycle-1). © 2016 American Chemical Society.

All-solid-state lithium batteries, Disulfide pairs, LiTiS2, Thin films, Titanium sulfide

Amorphous films, Cathodes, Electric batteries, Electrodes, Ions, Lithium, Lithium alloys, Lithium compounds, Lithium-ion batteries, Miniature batteries, Positive ions, Sulfur compounds, Thin films, Titanium, All-solid-state lithium battery, All-solid-state lithium ion batteries, Disulfide pairs, Electrochemical process, High specific capacity, Lithium ion microbatteries, LiTiS₂, Titanium sulfide, Thin film lithium ion batteries