title: Powering Lithium-Sulfur Battery Performance by Propelling Polysulfide Redox at Sulfiphilic Hosts.
abstract: Lithium-sulfur (Li-S) battery system is endowed with tremendous energy density, resulting from the complex sulfur electrochemistry involving multielectron redox reactions and phase transformations. Originated from the slow redox kinetics of polysulfide intermediates, the flood of polysulfides in the batteries during cycling induced low sulfur utilization, severe polarization, low energy efficiency, deteriorated polysulfide shuttle, and short cycling life. Herein, sulfiphilic cobalt disulfide (CoS2) was incorporated into carbon/sulfur cathodes, introducing strong interaction between lithium polysulfides and CoS2 under working conditions. The interfaces between CoS2 and electrolyte served as strong adsorption and activation sites for polar polysulfides and therefore accelerated redox reactions of polysulfides. The high polysulfide reactivity not only guaranteed effective polarization mitigation and promoted energy efficiency by 10% but also promised high discharge capacity and stable cycling performance during 2000 cycles. A slow capacity decay rate of 0.034%/cycle at 2.0 C and a high initial capacity of 1368 mAh g(-1) at 0.5 C were achieved. Since the propelling redox reaction is not limited to Li-S system, we foresee the reported strategy herein can be applied in other high-power devices through the systems with controllable redox reactions.
authors.affiliation: Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Yuan
authors.affiliation: Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Hong-Jie
authors.initials: HJ
authors.lastname: Peng
authors.affiliation: Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Ting-Zheng
authors.initials: TZ
authors.lastname: Hou
authors.affiliation: Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Jia-Qi
authors.initials: JQ
authors.lastname: Huang
authors.affiliation: Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences , 27 Taoyuan South Road, Taiyuan 030001, China.
authors.forename: Cheng-Meng
authors.initials: CM
authors.lastname: Chen
authors.affiliation: Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Dai-Wei
authors.initials: DW
authors.lastname: Wang
authors.affiliation: Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Xin-Bing
authors.initials: XB
authors.lastname: Cheng
authors.affiliation: Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wei
authors.affiliation: Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
keywords: Lithium−sulfur batteries; carbon; cathode; polysulfide; redox reaction