title: Catalytic oxidation of Li2S on the surface of metal sulfides for Li-S batteries.
abstract: Polysulfide binding and trapping to prevent dissolution into the electrolyte by a variety of materials has been well studied in Li-S batteries. Here we discover that some of those materials can play an important role as an activation catalyst to facilitate oxidation of the discharge product, Li2S, back to the charge product, sulfur. Combining theoretical calculations and experimental design, we select a series of metal sulfides as a model system to identify the key parameters in determining the energy barrier for Li2S oxidation and polysulfide adsorption. We demonstrate that the Li2S decomposition energy barrier is associated with the binding between isolated Li ions and the sulfur in sulfides; this is the main reason that sulfide materials can induce lower overpotential compared with commonly used carbon materials. Fundamental understanding of this reaction process is a crucial step toward rational design and screening of materials to achieve high reversible capacity and long cycle life in Li-S batteries.
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
authors.forename: Guangmin
authors.initials: G
authors.lastname: Zhou
authors.affiliation: School of Materials Science and Engineering, Beihang University, Beijing 100191, People's Republic of China.
authors.forename: Hongzhen
authors.initials: H
authors.lastname: Tian
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
authors.forename: Yang
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
authors.forename: Xinyong
authors.initials: X
authors.lastname: Tao
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
authors.forename: Bofei
authors.initials: B
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
authors.forename: Rufan
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Institute of Materials Research and Engineering, Agency for Science, Technology and Research, Singapore 138634.
authors.forename: Zhi Wei
authors.initials: ZW
authors.lastname: Seh
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
authors.forename: Denys
authors.initials: D
authors.lastname: Zhuo
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
authors.forename: Yayuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
authors.forename: Jie
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
authors.forename: Chenxi
authors.initials: C
authors.lastname: Zu
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305.
authors.forename: David Sichen
authors.initials: DS
authors.lastname: Wu
authors.affiliation: School of Materials Science and Engineering, Beihang University, Beijing 100191, People's Republic of China; yicui@stanford.edu qianfan@buaa.edu.cn.
authors.forename: Qianfan
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305; yicui@stanford.edu qianfan@buaa.edu.cn.|Stanford Institute for Materials and Energy Sciences, Stanford Linear Accelerator Center National Accelerator Laboratory, Menlo Park, CA 94025.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
keywords: catalytic oxidation; graphene; lithium−sulfur batteries; metal sulfides; polysulfide adsorption