title: Lithium-sulfur battery cathode enabled by lithium-nitrile interaction.
abstract: Lithium sulfide is a promising cathode material for high-energy lithium ion batteries because, unlike elemental sulfur, it obviates the need for metallic lithium anodes. Like elemental sulfur, however, a successful lithium sulfide cathode requires an inherent mechanism for preventing lithium polysulfide dissolution and shuttling during electrochemical cycling. A new scheme is proposed to create composites based on lithium sulfide uniformly dispersed in a carbon host, which serve to sequester polysulfides. The synthesis methodology makes use of interactions between lithium ions in solution and nitrile groups uniformly distributed along the chain backbone of a polymer precursor (e.g., polyacrylonitrile), to control the distribution of lithium sulfide in the host material. The Li(2)S-carbon composites obtained by carbonizing the precursor are evaluated as cathode materials in a half-cell lithium battery, and are shown to yield high galvanic charge/discharge capacities and excellent Coulombic efficiency, demonstrating the effectiveness of the architecture in homogeneously distributing Li(2)S and in sequestering lithium polysulfides.
authors.affiliation: School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, USA. jguo@engr.ucr.edu
authors.forename: Juchen
authors.initials: J
authors.lastname: Guo
authors.forename: Zichao
authors.initials: Z
authors.lastname: Yang
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Yu
authors.forename: Héctor D
authors.initials: HD
authors.lastname: Abruña
authors.forename: Lynden A
authors.initials: LA
authors.lastname: Archer