ScholarWorks@성균관대학교

초록

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.

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