Tuning Fe2TiO5 through Sn substitution for superior lithium storage and cycling stability

초록

Fe2TiO5 pseudobrookite demonstrate superb electrochemical performance as a negative electrode material in lithium-ion batteries (LIBs), owing to its distinctive crystal structure and the presence of multiple redox couples, which are indicative of potential ultrafast charging capabilities and robust cycling stability. This study explores this potential by synthesizing tin-substituted iron titanate (Fe2Ti1-xSnxO5) samples via a standard ceramic route. The successful incorporation of Sn4+ ions into the Fe2TiO5 host lattice results in a systematic expansion of the unit cell volume and an increased Ti4+/Ti3+ ratio. These structural and chemical modifications work in combination to improve the material's electrical conductivity. The as-synthesized Fe2Ti0.85Sn0.15O5 composite displays excellent electrochemical performance in LIBs application, with maximum discharge capacity retention of 402.4 mAh g(-1) (0.1 A g(-1)) after 100 continuous charge-discharge cycles, demonstrating remarkable long-term cycling stability. Furthermore, the composite reflects superior rate performance, retaining high discharge capacity of 342.0 mAh g(-1) even at a very high current density of 5 A g(-1). The optimized structural framework, high reversible capacity, outstanding rate kinetics, and strong cycle stability make Fe2Ti1-xSnxO5 a desirable and sustainable anode material for next-generation LIBs.

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