Cobalt nanofibers coated with layered nickel silicate coaxial core-shell composites as excellent anode materials for lithium ion batteries

A novel type of cobalt nanofibers coated with layered nickel silicate (Co nanofibers @ voids @ Ni₃Si₂O₅(OH)₄) coaxial core-shell composites were successfully prepared via a well-known Stöber process and two hydrothermal methods. In the composites, the international nanosheet structure of the nickel silicate provided interlayer spaces for lithium ions in the process of insertion and extraction. The cobalt nanofibers served as a mechanical support for the nickel silicate nanosheets, which increased the electrical conductivity of the whole electrode. In addition, one-dimensional coaxial structure was stable to buffer the volume change and avoid the destruction of the structure. Moreover, the voids provided effective channels for the transportation of lithium ions. The Co nanofibers @ voids @ Ni₃Si₂O₅(OH)₄) coaxial core-shell composites presented superior electrochemical properties compared with the published Ni₃Si₂O₅(OH)₄-related materials. With the advantages of exceptional performances and facile preparation, the composites show prospective application potential as advanced anode materials in lithium ion batteries.