A sandwich-like silicon-carbon composite prepared by surface-polymerization for rapid lithium-ion storage

摘要

Silicon-based materials are showing appealing potentials for electrical energy storage because of their unparalleled theoretical energy density.In this work,a rapid and efficient surface-polymerization processing has been developed to obtain a sandwich-like silicon-carbon composite structure for fast lithium storage.The anchored silicon particles are connected with a low diffusion tortuosity in the designed structure that facilitates the electron transport throughout the electrode and enhances the response rate under high current density.Electrochemical measurements demonstrate that the silicon-carbon composite electrode exhibits a high capacity for lithium storage.It shows a reversible capacity of 1990 mA h g~(-1) at 0.5 C after 100 cycles and also has an excellent capacity retention property (only-0.062% capacity reduction per cycle) in long-term cycling at 1 C.Furthermore,it can deliver a high reversible specific capacity of 1170 mA h g~(-1) even at 4 C.