Fe 2 VO 4 Hierarchical Porous Microparticles Prepared via a Facile Surface Solvation Treatment for High‐Performance Lithium and Sodium Storage

Preventing the aggregation of nanosized electrode materials is a key point to fully utilize the advantage of the high capacity. In this work, a facile and low‐cost surface solvation treatment is developed to synthesize Fe 2 VO 4 hierarchical porous microparticles, which efficiently prevents the aggregation of the Fe 2 VO 4 primary nanoparticles. The reaction between alcohol molecules and surface hydroxy groups is confirmed by density functional theory calculations and Fourier transform infrared spectroscopy. The electrochemical mechanism of Fe 2 VO 4 as lithium‐ion battery anode is characterized by in situ X‐ray diffraction for the first time. This electrode material is capable of delivering a high reversible discharge capacity of 799 mA h g −1 at 0.5 A g −1 with a high initial coulombic efficiency of 79%, and the capacity retention is 78% after 500 cycles. Moreover, a remarkable reversible discharge capacity of 679 mA h g −1 is achieved at 5 A g −1 . Furthermore, when tested as sodium‐ion battery anode, a high reversible capacity of 382 mA h g −1 can be delivered at the current density of 1 A g −1 , which still retains at 229 mA h g −1 after 1000 cycles. The superior electrochemical performance makes it a potential anode material for high‐rate and long‐life lithium/sodium‐ion batteries.