Hydrogenated Oxygen-Deficient Blue Anatase as Anode for High-Performance Lithium Batteries

摘要

Blue oxygen-deficient nanopartides of anatase TiO2 (H-TiO2) are synthesized using a modified hydrogenation process. Scanning electron microscope and transmission electron microscope images clearly demonstrate the evident change of the TiO2 morphology, from 60 nm rectangular nanosheets to much smaller round or oval nanopartides of similar to 17 nm, after this hydrogenation treatment. Importantly, electron paramagnetic resonance and positronium annihilation lifetime spectroscopy confirm that plentiful oxygen vacancies accompanied by Ti3+ are created in the hydrogenated samples with a controllable concentration by altering hydrogenation temperature. Experiments and theory calculations demonstrate that the well-balanced Li+/e(-) transportation from a synergetic effect between Ti3+/oxygen vacancy and reduced size promises the optimal H-TiO2 sample a high specific capacity, as well as greatly enhanced cycling stability and rate performance in comparison with the other TiO2.