title: Building better lithium-sulfur batteries: from LiNO3 to solid oxide catalyst.
abstract: Lithium nitrate (LiNO3) is known as an important electrolyte additive in lithium-sulfur (Li-S) batteries. The prevailing understanding is that LiNO3 reacts with metallic lithium anode to form a passivation layer which suppresses redox shuttles of lithium polysulfides, enabling good rechargeability of Li-S batteries. However, this view is seeing more challenges in the recent studies, and above all, the inability of inhibiting polysulfide reduction on Li anode. A closely related issue is the progressive reduction of LiNO3 on Li anode which elevates internal resistance of the cell and compromises its cycling stability. Herein, we systematically investigated the function of LiNO3 in redox-shuttle suppression, and propose the suppression as a result of catalyzed oxidation of polysulfides to sulfur by nitrate anions on or in the proximity of the electrode surface upon cell charging. This hypothesis is supported by both density functional theory calculations and the nitrate anions-suppressed self-discharge rate in Li-S cells. The catalytic mechanism is further validated by the use of ruthenium oxide (RuO2, a good oxygen evolution catalyst) on cathode, which equips the LiNO3-free cell with higher capacity and improved capacity retention over 400 cycles.
authors.affiliation: Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
authors.forename: Ning
authors.initials: N
authors.lastname: Ding
authors.affiliation: Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.|Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, Fudan University, Shanghai 200438, P.R. China.
authors.forename: Lan
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
authors.forename: Changwei
authors.initials: C
authors.lastname: Zhou
authors.affiliation: Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Geng
authors.affiliation: Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
authors.forename: Jin
authors.initials: J
authors.lastname: Yang
authors.affiliation: Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
authors.forename: Sheau Wei
authors.initials: SW
authors.lastname: Chien
authors.affiliation: Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
authors.forename: Zhaolin
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Institute of High Performance Computing (IHPC), A*STAR (Agency for Science, Technology and Research), 1 Fusionopolis Way, Connexis #16-16, Singapore 138632, Republic of Singapore.
authors.forename: Man-Fai
authors.initials: MF
authors.lastname: Ng
authors.affiliation: Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, Fudan University, Shanghai 200438, P.R. China.
authors.forename: Aishui
authors.initials: A
authors.lastname: Yu
authors.affiliation: Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.|Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Republic of Singapore.
authors.forename: T S Andy
authors.initials: TS
authors.lastname: Hor
authors.affiliation: Institute of High Performance Computing (IHPC), A*STAR (Agency for Science, Technology and Research), 1 Fusionopolis Way, Connexis #16-16, Singapore 138632, Republic of Singapore.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Sullivan
authors.affiliation: Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zong