Boosting polysulfide redox conversion of Li-S batteries by one-step-synthesized Co-Mo bimetallic nitride  

作　　者：Yingying Yan Hongtai Li Chen Cheng Tianran Yan Wenping Gao Jing Mao Kehua Dai Liang Zhang 

机构地区：[1]Institute of Functional Nano&Soft Materials(FUNSOM),Jiangsu Key Laboratory for Carbon-Based Functional Materials&Devices,Soochow University,Suzhou 215123,Jiangsu,China [2]School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,Henan,China [3]College of Chemistry,Tianjin Normal University,Tianjin 300387,China

出　　处：《Journal of Energy Chemistry》2021年第10期336-346,I0010,共12页能源化学（英文版）

基　　金：supported by the Collaborative Innovation Center of Suzhou Nano Science&Technology;the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD);the 111 project;the Joint International Research Laboratory of CarbonBased Functional Materials and Devices;the National Natural Science Foundation of China(11905154);the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(19KJA550004);the Natural Science Foundation of Jiangsu Province(BK20190814)。

摘　　要：Lithium-sulfur(Li-S)batteries are considered as one of the most promising next generation energy storage systems due to the high theoretical specific capacity,low cost,and environmental benignity.However,the notorious shuttle effect of polysulfides hinders the practical application of Li-S batteries.Herein,we have rationally designed and synthesized sea urchin-like Co-Mo bimetallic nitride(Co_(3) MO_(3) N)in the absence of additional nitrogen sources with only one step,which was applied as the sulfur host materials for Li-S batteries.The results indicate that Co_(3) Mo_(3) N can efficiently anchor and catalyze the conversion of polysulfides,thus accelerating the electrochemical reaction kinetics and enabling prominent electrochemical properties.As a consequence,the S@Co_(3) Mo_(3) N cathode exhibits a high rate performance of 705 mAh g^(-1) at 3 C rate and an excellent cycling stability with a low capacity fading rate of 0.08%per cycle at 1 C over 600 cycles.Even at a high sulfur loading of 5.4 cmg cm^(-2),it delivers a high initial areal capacity of 4.50 mAh cm^(-2) which is still retained at 3.64 mAh cm^(-2) after 120 cycles.Furthermore,the catalytic mechanism and structural stability of Co_(3) Mo_(3) N during cycling were elucidated by a combination of X-ray photoelectron spectroscopy and X-ray absorption fine structure.This work highlights the strategy of structure-catalysis engineering of bimetallic nitride,which is expected to have a wide application in Li-S batteries.

关 键 词：Lithium-sulfur batteries Co3Mo3N Shuttle effect Catalytic effect XAFS 

分 类 号：TM912[电气工程—电力电子与电力传动] O643.36[理学—物理化学]