Three-Dimensional Polyaniline-Coated Si/Reduced Graphene Oxide as High-Performance Anode Material for Lithium-Ion Batteries

Silicon is one of the most attractive anode materials for next-generation lithium-ion batteries due to its super-high theoretical specific capacity of 4200 mAh/g. However, due to the low intrinsic conductivity of Si and the unexpected change of Si volume in the process of lithium / lithium removal, the poor cycle stability and battery deformation are still caused. Herein, three-dimensional polyaniline-coated Si/reduced graphene oxide (PANI/Si@RGO) was synthesized by in-situ solvothermal method as anode material for lithium-ion batteries. The PANI was homogeneously coated on the surface of Si nanoparticles which could minimize the volume expansion effect due to the elastic property of PANI. Meanwhile, RGO and PANI in the networks could greatly enhance the electrical conductivity of Si nanoparticles. As a result, this PANI/Si@RGO composite presents a high reversible capacity with much improved cycling ability and rate performance (over 880 mAh/g after 200 cycles at 1 A/g with 84% capacity retention) compared with the pure Si anode. This three-dimensional Si nanocomposite shows good potential application for high-performance lithium-ion batteries.