Introducing reduced graphene oxide to improve the electrochemical performance of silicon-based materials encapsulated by carbonized polydopamine layer for lithium ion batteries

To improve the electrochemical performance of silicon-based anode material, the silicon/carbonized polydopamine/graphene (Si/PDAC/rGo) was prepared via pre-coating process in which graphene oxide was added and subsequent annealing process. The silicon particles with polydopamine (PDA) layer was encapsulated by graphene sheets due to interaction between the amine groups on PDA and the oxygen-containing groups on graphene oxide (GO), so the aggregation of silicon particles was hindered. The X-ray photoelectron spectroscopy (XPS) results present that most of the oxygen-containing groups were removed and the carbon layer contained nitrogen element. The initial coulombic efficiencies of Si/PDAC/rGo were 83.8%, 84.3%, 83.1% at 0.1, 0.3, 0.5 A g−1, respectively. The cycle and rate performance of Si/PDAC/rGo was also enhanced ascribed to the synergistic buffer effects of carbonized polydopamine layer and graphene sheets.