Re-delocalization of localized d-electrons in VO_(2)(R)-VS_(4)hetero-structure enables high performance of rechargeable Mg-ion batteries  

作　　者：Lijiao Zhou Chao Shen Xueyang Hou Zhao Fang Ting Jin Keyu Xie 

机构地区：[1]School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China [2]School of Metallurgical Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,China

出　　处：《Journal of Magnesium and Alloys》2024年第5期1830-1840,共11页镁合金学报（英文）

基　　金：the financial support of this work by the National Natural Science Foundation of China(No.52034011);the Key R&D Program of Shanxi(No.2019ZDLGY04-05);the National Natural Science Foundation of Shaanxi(No.2019JLZ-01);the Fundamental Research Funds for the Central Universities(No.G2020KY05129);the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(No.2020-BJ-03)。

摘　　要：Rechargeable Mg-ion batteries(MIBs)have attracted much more attentions by virtue of the high capacity from the two electrons chemistry.However,the reversible Mg^(2+)diffusion in cathode materials is restricted by the strong interactions between the high-polarized bivalent Mg^(2+)ions and anionic lattice.Herein,we design and propose a hetero-structural VO_(2)(R)-VS_(4)cathode,in which the re-delocalized d-electrons can effectively shield the polarity of Mg^(2+)ions.Theoretically,the electrons should spontaneously transfer from VS_(4)to VO_(2)(R)through the interfaces of hetero-structure due to the lower work function value of VS_(4).Furthermore,the internal electrons transfer lead to the electronic injection into VO_(2)(R)from VS_(4)and the partially broken V-V dimers,indicating the presence of lone pair electrons and charge re-delocalization.Benefiting from the shield effect of re-delocalized electrons,and the weakened attraction between cations and O/S anions enables more S^(2-)-S_(2)^(2-)redox groups to participate the electrochemical reactions and compensate the double charge of Mg^(2+)ions.Accordingly,VO_(2)(R)-VS_(4)hetero-structure exhibits a high specific capacity of 554 mA h g^(-1)at 50 mA g^(-1).It is believed that the charge re-delocalization of cathode extremely boost the Mg^(2+)ions migration for the high-capacity of MIBs.

关 键 词：Mg-ion batteries Cathode Charge delocalization Electronic structure HETEROSTRUCTURE 

分 类 号：TM912[电气工程—电力电子与电力传动] O646[理学—物理化学]