title: Enhancing the reversibility of Mg/S battery chemistry through Li(+) mediation.
abstract: Mg metal is a promising anode material for next generation rechargeable battery due to its dendrite-free deposition and high capacity. However, the best cathode for rechargeable Mg battery was based on high molecular weight MgxMo3S4, thus rendering full cell energetically uncompetitive. To increase energy density, high capacity cathode material like sulfur is proposed. However, to date, only limited work has been reported on Mg/S system, all plagued by poor reversibility attributed to the formation of electrochemically inactive MgSx species. Here, we report a new strategy, based on the effect of Li(+) in activating MgSx species, to conjugate a dendrite-free Mg anode with a reversible polysulfide cathode and present a truly reversible Mg/S battery with capacity up to 1000 mAh/gs for more than 30 cycles. Mechanistic insights supported by spectroscopic and microscopic characterization strongly suggest that the reversibility arises from chemical reactivation of MgSx by Li(+).
authors.forename: Tao
authors.initials: T
authors.lastname: Gao
authors.forename: Malachi
authors.initials: M
authors.lastname: Noked
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Pearse
authors.forename: Eleanor
authors.initials: E
authors.lastname: Gillette
authors.forename: Xiulin
authors.initials: X
authors.lastname: Fan
authors.forename: Yujie
authors.initials: Y
authors.lastname: Zhu
authors.forename: Chao
authors.initials: C
authors.lastname: Luo
authors.forename: Liumin
authors.initials: L
authors.lastname: Suo
authors.forename: Marshall A
authors.initials: MA
authors.lastname: Schroeder
authors.affiliation: Electrochemistry Branch, Power and Energy Division Sensor and Electron Devices Directorate, U.S. Army Research Laboratory , Adelphi, Maryland 20783, United States.
authors.forename: Kang
authors.initials: K
authors.lastname: Xu
authors.forename: Sang Bok
authors.initials: SB
authors.lastname: Lee
authors.forename: Gary W
authors.initials: GW
authors.lastname: Rubloff
authors.forename: Chunsheng
authors.initials: C
authors.lastname: Wang