title: Al2O3coated metal sulfides: one-pot synthesis and enhanced lithium storage stability via localized in situ conversion reactions.
abstract: Transition metal sulfides with high specific capacity have received increasing research interest in lithium storage. However, the low reversibility of metal sulfides usually leads to the oxidation of Li2S into polysulfides. The dissolution of polysulfides will suppress the regeneration of sulfides due to the loss of Li2S, which usually leads to poor cycling stability of sulfides. Herein, Al2O3coated Ni3S4nanoparticles (Ni3S4@Al2O3) have been rationally designed and fabricated via a one-pot hydrothermal process. The regeneration of nickel sulfides, which is the key to cycling stability of sulfides, can be promoted by the localized conversion from metal to metal sulfides because the Al2O3layer can prevent the diffusion and dissolution of polysulfides. The conversion of Al2O3to ion-conductive AlF3can enhance the quick charge transfer process of the lithium ion insertion/extraction reaction. Furthermore, the Al2O3/AlF3layer can also prevent the growth and aggregation of Ni3S4nanoparticles to retain the structure of the electrodes during the cycling process. The as-prepared Ni3S4@Al2O3exhibits a high reversible capacity of 651 mA h g-1at 500 mA g-1even after 400 cycles. This method can also be extended to other metal sulfides for improving electrochemical performances.
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China. xfqian@sjtu.edu.cn zaijiantao@sjtu.edu.cn.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China. xfqian@sjtu.edu.cn zaijiantao@sjtu.edu.cn.
authors.forename: Jiantao
authors.identifier: http://orcid.org/0000-0001-7562-6233
authors.initials: J
authors.lastname: Zai
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China. xfqian@sjtu.edu.cn zaijiantao@sjtu.edu.cn.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Li
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China. xfqian@sjtu.edu.cn zaijiantao@sjtu.edu.cn.
authors.forename: Zi-Feng
authors.initials: ZF
authors.lastname: Ma
authors.affiliation: Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering and State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China. xfqian@sjtu.edu.cn zaijiantao@sjtu.edu.cn.
authors.forename: Xuefeng
authors.identifier: http://orcid.org/0000-0002-8199-6502
authors.initials: X
authors.lastname: Qian