Constructing a "pea-pod"-like nanostructure to provide valid conductive matrix and volume change accommodation for silicon anode in lithium ion batteries

A "pea-pod"-like composite of graphene-wrapped silicon nanoparticles (P–Si@GS) was successfully prepared via a new and facial technique utilizing freeze-drying and subsequent solvothermal process. The cross-linked "pods" formed by curled few-layer graphene sheets constituted a conductive network, in which silicon nanoparticles were tightly wrapped. The unique graphene-wrapped structure with mesopores on the surface can effectively enhance the conductivity of silicon, alleviate its volume effect and provide rapid transport channels for electrons and ions, thus resulting in excellent electrochemical performance. The strategy of combining freeze-drying and solvothermal methods is facile, low-cost and effective, which provides new ideas for the preparation of high-performance graphene-wrapped nanoparticles composites.