Core–shell nano-structured carbon composites based on tannic acid for lithium-ion batteries
Core–shell nano-structured carbon composites have been used as electrode materials in lithium-ion batteries (LIBs) with increasing attention. The large volume swing during lithiation/delithiation processes and poor electronic conductivity are two key issues in the newly-proposed electrode materials, which severely limit their practical applications in LIBs. In order to solve these problems, we report a facile and versatile method to prepare core–shell nano-structured carbon composites using low cost and widely available tannic acid as the carbon source. The carbon layers with controlled thicknesses of 6–12 nm and 1–3 nm were coated on the surface of Si and TiO2 nanoparticles, respectively. Due to the carbon layers, both the Si@C and TiO2@C nanocomposites used as anode materials in LIBs showed excellent electrochemical performances including good cycling stability and high rate capability. We believe that this method may be applicable to various carbon-coating nanocomposites.