Cation vacancy engineering is considered to be one of the effective methods to solve the issues of shut-tling and sluggish redox kinetics of LiPSs 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(Fe0.96S)as a sulfur host.For this host structure,Fe0.96S is first employed as an adsorbent and catalyst in Li-S system.During the carbonization process,a tight contact structure of Fe0.96S crystal and carbon network(Fe0.96S@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 FeS crystal,the adsorption capability and catalytic effect for LiPSs have been substantially enhanced.Moreover,the presence of Fe0.96S 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 Fe0.96S and carbon,the Fe0.96S@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/cm2,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 fur-nishes a universal mentality for designing both divinable and astonishing new cation-vacancy materials.

Rongrong Li;Hao Sun;Caiyun Chang;Yuan Yao;Xiong Pu;Wenjie Mai

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;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;State Key Laboratory of Power Transmission Equipment and System Security and New Technology,School of Electrical Engineering,Chongqing University,Chongqing 400044,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China

能源化学

[1]Rongrong Li;Hao Sun;Caiyun Chang;Yuan Yao;Xiong Pu;Wenjie Mai-.In situ induced cation-vacancies in metal sulfides as dynamic electrocatalyst accelerating polysulfides conversion for Li-S battery)[J].能源化学,2022(12):74-82

tling,96S,Noting,nishes,divinable

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