Harmonized Bronze/Anatase/Rutile Multiphase Conjugated TiO₂-Carbon Nanoarchitecture Anode from Ti-Based Metal-Organic Frameworks for Enhanced Lithium-Ion Battery Performance

The increasing demand for high-rate and long-life lithium-ion batteries (LIBs) has highlighted the need for anode materials with fast kinetics, high capacity, and excellent stability. Titanium dioxide (TiO₂) is a promising candidate because of its safe and stable structure. However, it suffers from poor conductivity and slow lithium-ion diffusion. Herein, a multiphase TiO₂-carbon nanocomposite is reported that is composed of bronze (B), anatase (A), and rutile (R) phases termed BAR TiO₂, which is synthesized via the two-stop pyrolysis of Ti-based metal-organic frameworks (Ti-MOFs). This process allows control of the surface potential and Ti-OH interactions, leading to densely packed BAR interfaces embedded within a conductive carbon matrix. The BAR electrode delivers a high reversible capacity of 391 mAh g⁻¹ at 0.3 A g⁻¹ and retains 163 mAh g⁻¹ over 9000 cycles at 10 A g⁻¹. This outstanding performance stems from the synergistic combination of the fast lithium charge transport in TiO₂-R, the pseudocapacitive behavior of nanoscale TiO₂-B, and the structural robustness of TiO₂-A. In addition, MOF-derived carbon enhances the electronic conductivity and interfacial stability. The findings demonstrate that multiphase engineering combined with rational carbon integration is a promising approach for overcoming the intrinsic limitations of TiO₂-based anodes in advanced LIB technologies.