Decorating ketjen black with ultra-small Mo_(2)C nanoparticles to enhance polysulfides chemisorption and redox kinetics for lithium-sulfur batteries

作     者：Nan Jiang Guangyu Jiang Dechao Niu Jiayi Mao Meiwan Chen Kaiyuan Li Yongsheng Li Nan Jiang;Guangyu Jiang;Dechao Niu;Jiayi Mao;Meiwan Chen;Kaiyuan Li;Yongsheng Li

作者机构：Lab of Low-Dimensional Materials ChemistryKey Laboratory for Ultrafine Materials of Ministry of Education.School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2020年第29卷第12期

页      面：207-215页

核心收录：

学科分类：0820[工学-石油与天然气工程] 0808[工学-电气工程] 08[工学] 0817[工学-化学工程与技术] 0807[工学-动力工程及工程热物理] 0827[工学-核科学与技术] 0703[理学-化学] 

基　　金：financially supported by the National Natural Science Foundation of China for Innovative Research Groups (No. 51621002) the National Key Research and Development Program of China (Grant No. 2016YFA0203700) NSFC (Grant No 51672083) Program of Shanghai Academic/Technology Research Leader (18XD1401400) Basic Research Program of Shanghai (17JC1404702) Leading talents in Shanghai in 2018 The Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, the 111 project (B14018) The Fundamental Research Funds for Central Universities (222201718002)。 

主　　题：in-situ growth Ultra-small Mo_(2)C Catalytic effect Chemisorption Multifunctional separator Lithium-sulfur batteries 

摘      要：The low sulfur utilization and fast capacity fading resulting from the sluggish redox reaction and abominable polysulfides shuttle greatly hinder the practical applications of lithium-sulfur(Li-S) batteries.Herein, we develop a facile in-situ growth method to decorate ultra-small Mo2 C nanoparticles(USMo2 C) on the surface of Ketjen Black(KB) to functionalize the commercial polypropylene(PP) separators,which can accelerate the redox kinetics of lithium polysulfides conversion and effectively increase the utilization of sulfur for Li-S batteries. Importantly, the US-Mo2 C nanoparticles have abundant sites for chemical adsorption towards polysulfides and the conductive carbon networks of KB have cross-linked pore channels, which can promote electron transport and provide physical barrier and volume expansion space for polysulfides. Due to the combined effects of the US-Mo2 C and KB, Li-S cells employing the multifunctional PP separators modified with KB/US-Mo2 C composite(KB/US-Mo2 C@PP) exhibit a high specific capacity(1212.8 mAh g^(-1) at 0.2 C), and maintain a reversible capacity of 1053.3 m Ah g^(-1) after 100 cycles.More importantly, the KB/US-Mo2 C@PP cells with higher sulfur mass loading of 4.9 mg cm^(-2) have superb areal capacity of 2.3 mAh cm^(-2). This work offers a novel and promising perspective for high-performance Li-S batteries from both the shuttle effect and the complex polysulfides conversion.