Silicon/carbon nanocomposite pyrolyzed from phenolic resin as anode materials for lithium-ion batteries

Silicon/carbon nanocomposite as anode materials for lithium-ion batteries is synthesized by a simple route using phenolic resin as a precursor. The Si nanoparticles with the size of 50–200 nm in diameter can be uniformly coated by carbon layer when the content of carbon is 58%. As an anode material for lithium-ion batteries, the Si/C nanocomposite exhibits a reversible capacity of 678 mAh g−1 after 50 cycles at a current density of 100 mA g−1as well as excellent capacity retention at high rates. These improvements could be attributed to the introduction of carbon in the Si/C nanocomposite and carbon coatings on the surface of Si, which provide a rapid lithium transport pathway, reduce the cell impedance and stabilize the electrode structure during charge/discharge cycles. ► Si/C nanocomposite is prepared by using phenolic resin as a carbon precursor. ► The Si particles are covered by a uniform nanosized carbon layer. ► Si/C nanocomposite exhibits higher electrochemical performance than bare Si and C. ► The capacity can be tuned by varying the ratio of Si to C.