High storage performance of core–shell Si@C nanoparticles as lithium ion battery anodematerial

Core–shell Si@C nanoparticles have been obtained by heat treating the organic precursor decorated Si crystalline nanoparticles successfully. The method of decorating organic precursor by the chemical reaction is so controllable that the coated carbon shell on the Si nanoparticles is uniformly ultrathin. This ultrathin carbon shell realizes effective relief to the capacity fading of Si nanoparticles with low carbon content in the composite. Electrochemical measurements demonstrate that the core–shell Si@C nanoparticles behave a so stable cycle performance as anode material of lithium ion batteries with a vinylene carbonate containing electrolyte, that the capacity still remains 1700 mA h g−1 after 50 cycle charge/discharge.

► A controllable and facile method was proposed to synthesize core–shell Si@C nanoparticles.
► The carbon shell was uniformly ultrathin (low than 10 nm).
► The capacity of the Si@C nanoparticle anodes after 50 cycles was more than 1700 mA h g−1.