Recyclable cobalt-molybdenum bimetallic carbide modified separator boosts the polysulfide adsorption-catalysis of lithium sulfur battery  

钴-钼双金属碳化物修饰隔膜强化锂硫电池中多硫化锂的吸附和催化转化

作　　者：Ze Zhang Jia-Nan Wang A-Hu Shao Dong-Gen Xiong Jian-Wei Liu Cheng-Yen Lao Kai Xi Shi-Yao Lu Qiu Jiang Ji Yu Huang-Long Li Zhen-Yu Yang R.Vasant Kumar 张泽;王嘉楠;邵啊虎;熊冬根;刘建伟;劳成琰;郗凯;芦世瑶;江秋;吁霁;李黄龙;杨震宇;R.Vasant Kumar(School of Chemistry,Nanchang University,Nanchang 330031,China;Department of Materials Science and Metalliclurgy,University of Cambridge,Cambridge CB30FS,UK;Department of Environmental Science and Engineering,Department of Applied Chemistry,School of Science,Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter(Ministry of Education),State Key Laboratory for Electrical Insulation and Power Equipment,Xi’an Jiaotong Univrsity,Xi’an 710049,China;Department of Engineering,University of Cambridge,CB30FA Cambridge,UK;Department of Chemistry,City University of Hong Kong,Tat Chee Avenue,Kowloon,Hong Kong,China;Department of Precision Instrument,Tsinghua University,Beijing 10084,China)

机构地区：[1]School of Chemistry,Nanchang University,Nanchang 330031,China [2]Department of Materials Science and Metalliclurgy,University of Cambridge,Cambridge CB30FS,UK [3]Department of Environmental Science and Engineering,Department of Applied Chemistry,School of Science,Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter(Ministry of Education),State Key Laboratory for Electrical Insulation and Power Equipment,Xi’an Jiaotong Univrsity,Xi’an 710049,China [4]Department of Engineering,University of Cambridge,CB30FA Cambridge,UK [5]Department of Chemistry,City University of Hong Kong,Tat Chee Avenue,Kowloon,Hong Kong,China [6]Department of Precision Instrument,Tsinghua University,Beijing 10084,China

出　　处：《Science China Materials》2020年第12期2443-2455,共13页中国科学（材料科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(21863006,51662029,61974082 and 61704096);Youth Science Foundation of Jiangxi Province(20192BAB216001);Key Laboratory of Jiangxi Province for Environment and Energy Catalysis(20181BCD40004)。

摘　　要：The polysulfide shuttling and sluggish redox kinetics,due to the notorious adsorption-catalysis underperformance,are the ultimate obstacles of the practical application of lithium-sulfur(Li-S)batteries.Conventional carbon-based and transition metal compound-based material solutions generally suffer from poor catalysis and adsorption,respectively,despite the performance gain in terms of the other.Herein,we have enhanced polysulfide adsorptioncatalytic capability and protected the Li anode using a complementary bimetallic carbide electrocatalyst,Co3 Mo3 C,modified commercial separator.With this demonstration,the potentials of bimetal compounds,which have been well recognized in other environmental catalysis,are also extended to Li-S batteries.Coupled with this modified separator,a simple cathode(S/Super P composite)can deliver high sulfur utilization,high rate performance,and excellent cycle stability with a low capacity decay rate of^0.034%per cycle at 1 C up to1000 cycles.Even at a high S-loading of 8.0 mg cm^-2 with electrolyte/sulfur ratio=6 m L g^-1,the cathode still exhibits high areal capacity of^6.8 m A h cm^-2.The experimental analysis and the first-principles calculations proved that the bimetallic carbide Co3 Mo3 C provides more binding sites for adsorbing polysulfides and catalyzing the multiphase conversion of sulfur/polysulfide/sulfide than monometallic carbide Mo2 C.Moreover,the modified separator can be reutilized with comparable electrochemical performance.We also showed other bimetallic carbides with similar catalytic effects on Li-S batteries and this material family has great promise indifferent energy electrocatalytic systems.本文报道了一种钴-钼双金属碳化物(Co3Mo3C)催化材料用于修饰锂硫电池隔膜,强化多硫化锂的化学吸附和催化转化.所组装的电池表现出优异的电化学性能,即使在8.0 mg cm^-2的硫面积负载量条件下,面积比容量仍高达6.8 mA h cm^-2.理论计算结果表明,相比于单一金属碳化物Mo2C,双金属碳化物Co3Mo3C具有更多的活性位点,更利于化学固定多硫化锂,并催化多硫化锂间相互转化;同时,Ni3Mo3C和Fe3Mo3C亦表现出类似的高催化活性.本研究对高性能锂硫电池关键催化材料的设计具有一定的指导意义.

关 键 词：lithium-sulfur batteries bimetallic carbides electrocatalysts polysulfide adsorption-catalysis modified separators 

分 类 号：TM912[电气工程—电力电子与电力传动] TB383.2[一般工业技术—材料科学与工程]