Energy Materials Scientific Journals

Energy Materials Scientific Journals

Herein, a crystallization-induced surface defect engineering to promote the electrochemical activity of LT by electronic structure modulation and diffusion kinetics regulation is proposed. As evidenced by electrochemical characterization, this surface defect modification strategy can effectively reduce the polarization and facilitate fast electronic/ionic diffusion of titanates. Thereby, the targeted low-crystalline layer modified layered titanate (LC-LT) unfolds enhanced rate capability and cycle stability (8000 cycles, 88%). Theoretical calculations reveal that the LC-LT is equipped with narrower bandgap originated from the 3d orbital of oxygen vacancies-induced defective Ti atoms on the surface. Moreover, reduced Na+ migration energies and interconnected Na+ diffusion pathways are predicted in LC-LT by density functional theory (DFT) calculations and bond valence site energy (BVSE) analysis. When applied in Na-ion full cell with NASICON-type Na3V2(PO4)2F3 cathode, the configuration exhibits comparable rate performance and cycle stability (800 cycles, 81.6%).


Last Updated on: Nov 28, 2024

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