H 1.07 Ti 1.73 O 4 -Derived Porous Plate-like TiO 2 as High-Performance Bifunctional Anodes for Lithium- and Sodium-Ion Batteries

Porous plate-like anatase TiO 2 particles were synthesized through a direct calcination approach using layered titanate H 1 . 07 Ti 1 . 73 O 4 as a precursor. By controlling the calcination temperature (400 °C, 500 °C, and 600 °C), the morphology and electrochemical properties of the TiO 2 samples were effectively tuned. When evaluated as anodes for lithium-ion batteries (LIBs), the porous TiO 2 materials demonstrated markedly improved rate performance compared to commercial nano-TiO 2 (n-TiO 2 ). Specifically, at a high current density of 5.0 A/g, p-TiO 2 -500 and p-TiO 2 -600 delivered discharge capacities of 70.5 mAh/g and 87.5 mAh/g, respectively, far exceeding the 27.7 mAh/g achieved by n-TiO 2 . The corresponding capacity retention rates at this rate were 30.1% for p-TiO 2 -500, 41.2% for p-TiO 2 -600, and only 16.4% for n-TiO 2 . The enhancement in kinetics is ascribed to the unique porous plate-like architecture, which promotes efficient ion transport and introduces significant pseudocapacitive contributions. When applied as anodes for sodium-ion batteries (SIBs), p-TiO 2 -600 exhibited the most promising performance. This study underscores the potential of porous plate-like TiO 2 as a high-performance bifunctional anode material suitable for both LIBs and SIBs.