High-capacity flour-based nano-Si/C composite anode materials for lithium-ion batteries

A facile, low cost, and low equipment-requirement preparation route of Si/C composite was developed. Naturally porous flour was carbonized through a conformal carbonization process and a further activation process in vacuum, obtaining flour-derived porous carbon (FPC) with ample pores. FPC was used to load nano-silicon through electrostatic adsorption method. Si-FPC was coated by sucrose-derived carbon (SC) shell by aqueous evaporation method to obtain Si-FPC-SC. Benefitting from FPC's good dispersion for silicon, 40%-Si-FPC delivers a reversible capacity of 1562 mAh g(-1), equivalent to 83% of pure nano-silicon's reversible capacity, an outstanding rate performance of 761 mAh g(-1) at 1 A g(-1) current density. The final 30%-Si-FPC-SC exhibits a reversible capacity of 937 mAh g(-1) at 0.1 A g(-1), a cyclic retention of 82.3% after 100 cycles. Furthermore, the synthetic method of Si/C composites offers a universal idea for the research of high-capacity anode materials for lithium-ion batteries.