Influence of TiO2 Particle Size on the Synthesis of Titanium–Niobium Oxides and Their Electrochemical Performance in Lithium–Ion Cells

Developing high-performance anode materials is crucial for advancing lithium-ion batteries, particularly to meet the growing demands for higher capacity, improved safety, and enhanced rate performance in applications such as electric vehicles. In this study, we reveal the significant impact of the TiO₂ particle size on the synthesis and electrochemical performance of titanium–niobium oxides (TNOs). Using a high-temperature solid-phase method, we synthesized TNOs with varying compositions and sizes by reacting TiO₂ particles of different sizes (5–10, 10–25, 30, 60, and 100 nm) with Nb₂O₅ particles. Comprehensive characterization through X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and electrochemical tests revealed that the TNO synthesized using 10–25 nm TiO₂ particles (designated as TNO4) exhibited superior electrochemical performance. TNO4 demonstrated the highest charge/discharge capacities at high current densities and exceptional cycling stability, which can be attributed to its optimal composition and particle size, both of which facilitate efficient lithium-ion diffusion and electron transport. This work not only highlights the critical role of precursor particle size in tailoring the properties of TNO anode materials but also identifies the optimal TiO₂ particle size for synthesizing high-performance TNOs via a simple and scalable method. Additionally, this work underscores that both the composition and the particle size of TNOs significantly affect their electrochemical performance. Our findings provide valuable insights and serve as a practical reference for the design and preparation of advanced anode materials for lithium-ion batteries.