Ni0.85 Se hexagonal nanosheets as an advanced conversion cathode for Mg secondary batteries  

作　　者：Dong Chen Jingwei Shen Xue Li Shun-an Cao Ting Li Wei Luo Fei Xu 

机构地区：[1]Key Laboratory of Hydraulic Machinery Transients,Ministry of Education,School of Power and Mechanical Engineering,Wuhan University,Wuhan 430072,Hubei,China [2]Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission,Ministry of Education,College of Chemistry and Materials Science,South-Central University for Nationalities,Wuhan 430074,Hubei,China [3]College of Chemistry and Molecular Sciences,Wuhan University,Wuhan 430072,Hubei,China

出　　处：《Journal of Energy Chemistry》2020年第9期226-232,I0007,共8页能源化学（英文版）

基　　金：financially supported by Intergovernmental International Science and Technology Innovation Cooperation Project(2019YFE010186);the Hubei Provincial Natural Science Foundation(2019CFB452 and 2019CFB620);the Fundamental Research Funds for the Central Universities。

摘　　要：Mg secondary batteries are promising scalable secondary batteries for next-generation energy storage.However,Mg-storage cathode materials are greatly demanded to construct high-performance Mg batteries.Electrochemical conversion reaction provides plenty of cathode options,and strategy for cathode selection and performance optimization is of special significance.In this work,Ni0.85Se with nanostructures of dispersive hexagonal nanosheets(D-Ni0.85Se)and flower-like assembled nanosheets(F-Ni0.85Se)is synthesized and investigated as Mg-storage cathodes.Compared with F-Ni0.85Se,D-Ni0.85Se delivers a higher specific capacity of 168 mAh g^-1 at 50 mA g^-1 as well as better rate performance,owing to its faster Mg^2+-diffusion and lower resistance.D-Ni0.85Se also exhibits a superior cycling stability over 500cycles.An investigation on mechanism indicates an evolution of Ni0.85Se towards NiSe with cycling,and the Mg-storage reaction occurs between NiSe and metallic Ni^0.The present work demonstrates that advanced conversion-type Mg battery cathode materials could be constructed by soft selenide anions,and the electrochemical properties could be manipulated by rational material morphology optimization.

关 键 词：Mg secondary batteries Electrochemical conversion reaction Ni0.85Se Hexagonal nanosheets Diffusion kinetics 

分 类 号：TM912[电气工程—电力电子与电力传动] TB383.1[一般工业技术—材料科学与工程]