Nanostructured 3D porous hybrid network of N-doped carbon, graphene and Si nanoparticles as an anode material for Li-ion batteries

We report a facile and scalable process to prepare nanostructured 3D porous networks combining graphene, N-doped carbon and silicon nanoparticles (G@Si@C) as a promising anode material for batteries. It consists of preparing polymethylmethacrylate particles decorated by Si/graphene oxide and polypyrrole (PPy) in a one-pot process, followed by an appropriate thermal treatment that decomposes PMMA and converts graphene oxide into graphene and polypyrrole into N-doped carbon. The so-formed electrically conducting 3D porous network containing Si nanoparticles inside the cell walls accommodates the large volume changes of Si during charging/discharging and provides a fast electrolyte penetration/diffusion. Therefore, the designed G@Si@C material presents an excellent reversible capacity of 740 mA h g(-1) at a current density of 0.14 A g(-1) based on the total mass loading of the composite, with more than 99% coulombic efficiency, high rate capability and good cyclability, suggesting great potential for application as an anode material for lithium-ion batteries.