Covalently-functionalizing synthesis of Si@C core–shell nanocomposites as high-capacity anode materials for lithium-ion batteries

This paper reports the facile fabrication of Si@C core–shell nanocomposites by covalently grafting aniline monomer onto the surface of silicon nanoparticles, followed by a carbonizing process. Our covalently-functionalizing approach can lead to a uniform carbon coating with a tunable thickness and is low cost, environmentally friendly and easily scaled up. The Si@C nanocomposite was employed as an anode material for lithium-ion batteries (LIBs), showing a high initial reversible capacity of >1300 mA h g−1 as well as a good cycling stability. The enhanced performance is attributed to the fact that the uniform and elastic carbon coating can efficiently increase the electronic conductivity and accommodate severe volume changes of the Si particles. This Si@C nanocomposite exhibits great potential as an anode material in LIBs, and the fabrication strategy can be extended to prepare other carbon-coated core–shell nanocomposites.