Preparation of Fe2O3 nanoparticles with ultrathin carbon covered as lithium storage anodes

•Developed as anode materials for lithium-ion batteries using a simple hydrothermal method.•Fe2O3 NPs wrapped balloon-like in an ultrathin carbon coating for mitigating volume expansion.•DFT calculations show that C-doping in Fe2O3 reduces the band gap from 2.12 to 1.10 eV.•Fe2O3/C delivers far higher electrochemical performances than bare Fe2O3 NPs. This study focuses on the development of ultrathin carbon (UTC) treated with Fe2O3 nanoparticles as anode materials for lithium-ion batteries (LIBs). Here, a simple hydrothermal method has been adopted to prepare Fe2O3@C nanocomposite, followed by annealing. The obtained Fe2O3@C demonstrates Fe2O3 nanoparticles (NPs) with uniform carbon, which effectively mitigates volume expansion and enhances electrochemical performance. Encouraging, the first principal calculations ensure that carbon doping in Fe2O3 can notably reduce the band gap from 2.12 to 1.10 eV and enhance electronic conductivity.