Enhanced Lithium Storage Performance Derived from Fe2Ti1-xNixO5 (0 ≤ X ≤ 0.1) As a Fast Charging Anode

Using iron titanate (Fe2TiO5) as an electrode provides high theoretical capacity and good cycling stability because of its multiple redox couples and unique crystal structure. The synthesis of the material is successfully carried out using the conventional ceramic method. The effect of Ni2+ substitution on the overall electrochemical performance of Fe2Ti1-xNixO5 anode material is explored. When Ni2+ replaces Ti4+ in the pseudobrookite Fe2TiO5 unit cell, the volume increases smoothly with the amount of nickel and the electrical conductivity is enhanced because of the higher Ti3+/Ti4+ ratio. With pore sizes of around 10 nm and specific surface areas of 330.81 m2 g-1, Fe2Ti1-xNixO5 can provide large contact areas between the electrode and electrolyte and shorten the lithium-ion diffusion distance. With discharge capacities of 368.6 mAh g-1 at the 100th cycle, Fe2Ti1-xNixO5 negative electrode exhibits outstanding electrochemical performance. Furthermore, it demonstrates excellent rate stability, with a discharge capacity of 310.6 mAh g-1 at a current rate of 5000 mA g-1. Over another 45 cycles, a high discharge capacity of 367.1 mAh g-1 was maintained at a current density of 100 mA g-1 even after the rate performance test. The Ni2+ doping results in faster Li+ insertion/extraction kinetics due to reduced Li+ diffusion paths, which leads to performance improvement.