title: Dual Cation- and Anion-Based Redox Process in Lithium Titanium Oxysulfide Thin Film Cathodes for All-Solid-State Lithium-Ion Batteries.
abstract: 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 all-solid-state lithium-ion microbatteries are synthesized by sputtering of LiTiS2targets 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).
authors.affiliation: CNRS, Université de Bordeaux , ICMCB UPR 9048 and Bordeaux INP, F-33600 Pessac, France.|ST Microelectronics , 16 rue Pierre et Marie Curie, F-37071 Tours, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Dubois
authors.affiliation: CNRS, Université de Bordeaux , ICMCB UPR 9048 and Bordeaux INP, F-33600 Pessac, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Pecquenard
authors.affiliation: IPREM-ECP CNRS UMR 5234, Université de Pau , 2 avenue Pierre Angot, F-64053 Pau, France.
authors.forename: Samantha
authors.initials: S
authors.lastname: Soulé
authors.affiliation: IPREM-ECP CNRS UMR 5234, Université de Pau , 2 avenue Pierre Angot, F-64053 Pau, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Martinez
authors.affiliation: CEA LETI , Minatec Campus, 17 rue des Martyrs, F-38054 Grenoble, France.|Université Grenoble Alpes , F-38000 Grenoble, France.
authors.forename: Frédéric
authors.identifier: http://orcid.org/0000-0003-3436-8279
authors.initials: F
authors.lastname: Le Cras
keywords: LiTiS2; all-solid-state lithium batteries; disulfide pairs; thin films; titanium sulfide