α-Fe2O3 nanowall arrays: hydrothermal preparation, growth mechanism and excellent rate performances for lithium ion batteries

Abstract

α-Fe₂O₃ nanowall arrays (NWAs) were grown directly on Ni foam by a facile hydrothermal method. Based on time-dependent experiment results, a possible formation mechanism for this structure was proposed. The as-prepared α-Fe₂O₃ samples have an open network structure constituted of interconnected nanowalls and can be directly used as integrated electrodes for lithium-ion batteries (LIBs). The unique nanostructural feature is advantageous in electron transport and electrolyte diffusion efficiency, which can accelerate the electrochemical reaction. Thus, compared to a traditional electrode, the unique assembly reduces polarization of the electrode and results in excellent rate performances (440 mA h g⁻¹ at 5 C).