Refilling Nitrogen to Oxygen Vacancies in Ultrafine Tungsten Oxide Clusters for Superior Lithium Storage

Morphological engineering of nanosized transitional metal oxides shows great promise for performance improvement, yet limited efforts have been attempted to engineer the atomic structure. Oxygen vacancy (V-O) can boost charge transfer leading to enhanced performance; yet excessive V-O may impair the conductivity. Herein, tungsten oxide is atomically tailored by incorporating nitrogen heteroatoms into the oxygen vacancies. The efficient nitrogen-filling into the oxygen vacancies is evidenced by the electron paramagnetic resonance spectroscopy and X-ray absorption spectroscopy. The coordinated N atoms play a crucial role in facilitating the charge transfer and maintaining efficient lithium-ion diffusion. Consequently, the tungsten oxide with N-filled oxygen vacancies exhibits superior lithium-ion storage performance.