Silicon suboxide(SiOx,0＜x＜2)is recognized as one of the next-generation anode materials for high-energy-density lithium ion batteries(LIBs)due to its high theoretical specific capacity and abundant resource.However,the severe mechanical instability arising from large volume variation upon charge/discharge cycles frustrates its electrochemical performance.Here we propose a well-designed sandwich-like structure with sandwiched SiOx nanoparticles between graphene sheets and amorphous carbon-coating layer so as to improve the structural stability of SiOx anode materials during cycling.Graphene sheets and carbon layer together construct a three-dimensional conductive network around SiOx particles,which not only improves the electrode reactions kinetics,but also homogenizes local current density and thus volume variation on SiOx surface.Moreover,Si-O-C bonds between SiOx and graphene endow the strong particle adhesion on graphene sheets,which prevents SiOx peeling from graphene sheets.Owing to the synergetic effects of the structural advantages,the C/SiOx@graphene material exhib-its an excellent cyclic performance such as 890 mAh/g at 0.1 C rate and 73.7％capacity retention after 100 cycles.In addition,it also delivers superior rate capability with a capacity recovery of 886 mAh/g(93.7％recovery rate)after 35 cycles of ascending steps at current range of 0.1-5 C and finally back to 0.1 C.This study provides a novel strategy to improve the structural stability of high-capacity anode materials for lithium/sodium ion batteries.

Zhaolin Li;Yaozong Yang;Jie Wang;Zhao Yang;Hailei Zhao

School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China;Beijing Municipal Key Laboratory of New Energy Materials and Technologies,Beijing 100083,China

矿物冶金与材料学报

[1]Zhaolin Li;Yaozong Yang;Jie Wang;Zhao Yang;Hailei Zhao-.Sandwich-like structure C/SiOx@graphene anode material with high electrochemical performance for lithium ion batteries)[J].矿物冶金与材料学报,2022(11):1947-1953

frustrates,homogenizes

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