Amorphous Fe2O3 film-coated mesoporous Fe2O3 core-shell nanosphere prepared by quenching as a high-performance anode material for lithium-ion batteries

Ferric oxide (Fe2O3) is a promising anode material for lithium-ion batteries (LIBs) thanks to its high theoretical capacity and abundance. However, pure-phase Fe2O3 falls far short of its theoretical specific capacity during application, and most of the modification methods are complex as well as pollute the environment. In this work, a novel amorphous Fe2O3 film-coated mesoporous Fe2O3 crystalline core-shell structure (amFO@mFe(2)O(3)) with narrowed lattice and oxygen vacancy was synthesized through easy and operable annealing followed by a time-saving water quenching strategy. Benefiting from the special features after quenching, the optimized amFO@mFe(2)O(3) demonstrated exceptional electrochemical performance as the anode material for LIBs, achieving a specific capacity of similar to 1000 mAh.g(-1) after stabilization at 500 mA.g(-1), superior to the values of LIBs constructed by the bare crystalline Fe2O3. Excellent rate performance was exhib-ited up to 220 mAh.g(-1) at a high current density of 20,000 mAh.g(-1), and reversible capacity can be restored to approximately 1015 mAh.g(-1) when the current density returns to 100 mA.g(-1). This protocol provides an ultra-simple method to enhance the electrochemical performance of transition metal oxides anode for LIBs and would propel the development of new functional materials for energy storage and conversion.