In situ induced cation-vacancies in metal sulfides as dynamic electrocatalyst accelerating polysulfides conversion for Li-S battery  

作　　者：Rongrong Li Hao Sun Caiyun Chang Yuan Yao Xiong Pu Wenjie Mai 

机构地区：[1]Siyuan Laboratory,Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials,Department of Physics,Jinan University,Guangzhou 510632,Guangdong,China [2]CAS Center for Excellence in Nanoscience,Beijing Key Laboratory of Micro-Nano Energy and Sensor,Beijing Institute of Nanoenergy and Nanosystems,Chinese Academy of Sciences,Beijing 101400,China [3]State Key Laboratory of Power Transmission Equipment and System Security and New Technology,School of Electrical Engineering,Chongqing University,Chongqing 400044,China [4]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Energy Chemistry》2022年第12期74-82,I0003,共10页能源化学（英文版）

基　　金：supported by the National Natural Science Foundation of China(52173274 and 52172202);the Natural Science Foundation of Guangdong Province 2022A1515010049;the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA16021101);the China Postdoctoral Science Foundation(2021M691228)。

摘　　要：Cation vacancy engineering is considered to be one of the effective methods to solve the issues of shuttling and sluggish redox kinetics of Li PSs owing to the intrinsic tunability of electronic structure.However,cation vacancies are few studied in the Li-S realm due to their complex and rigid preparation methods.In this work,one-step pyrolysis is reported to in situ introduce Fe-vacancies into iron sulfide(Fe_(0.96)S)as a sulfur host.For this host structure,Fe_(0.96)S is first employed as an adsorbent and catalyst in Li-S system.During the carbonization process,a tight contact structure of Fe_(0.96)S crystal and carbon network(Fe_(0.96)S@C)is in situ constructed,and the carbon layer as a conductor provides smooth electrons transfer pathways for redox reactions.Meanwhile,due to the introduction of Fe-vacancies in Fe S crystal,the adsorption capability and catalytic effect for Li PSs have been substantially enhanced.Moreover,the presence of Fe_(0.96)S crystal favors the mobility of electron and diffusion of Li+,which is revealed by the experiments and theoretical calculations.Through synergy respective advantages effect of Fe_(0.96)S and carbon,the Fe_(0.96)S@C-S cathode delivers high-rate capability at 5.0 C and stable long-life performance.Even under a high sulfur loading of 3.5 mg/cm^(2),the durable cyclic stability is still exhibited with the capacity retention of 93%over 400 cycles at 1.0 C,and the coulombic efficiency is≥98%.Noting that this strategy greatly simplifies the synthetic process of currently known cation-vacancy materials and furnishes a universal mentality for designing both divinable and astonishing new cation-vacancy materials.

关 键 词：Cation vacancy Fe_(0.96)S@C structure Catalytic conversion Lithium-sulfur battery 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ426[化学工程]