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

Abstract

Amorphous Fe 2 O 3 films-coated mesoporous crystalline Fe 2 O 3 material was synthesized through an easy quenching strategy, demonstrating excellent electrochemical performance for LIBs. • Novel amorphous Fe 2 O 3 films coated mesoporous crystalline Fe 2 O 3 were synthesized. • Amorphous Fe 2 O 3 films provided more active sites and restrain the volume change during cycling. • AmFO@mFe 2 O 3 demonstrated high capacity and ideal cycling stability as anode for LIBs. • Iced water quenching method is low-cost, simplicity and suitable for scalable manufacture. Ferric oxide (Fe 2 O 3 ) is a promising anode material for lithium-ion batteries (LIBs) thanks to its high theoretical capacity and abundance. However, pure-phase Fe 2 O 3 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 Fe 2 O 3 film-coated mesoporous Fe 2 O 3 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 ∼ 1000 mAh·g −1 after stabilization at 500 mA·g −1 , superior to the values of LIBs constructed by the bare crystalline Fe 2 O 3 . Excellent rate performance was exhibited up to 220 mAh·g −1 at a high current density of 20,000 mA·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.