Tailoring Oxygen Vacancies in CoMoO4 for Superior Lithium Storage

Abstract The application of transition‐metal oxides in the energy storage field is hampered by its low electronic conductivity, sluggish Li + diffusion, and huge volume changes. The construction of oxygen vacancy defects can effectively modify the electronic structure of the active materials, accelerating the charge transfer process. Herein, the CoMoO 4 nanorods with different oxygen vacancy concentrations are synthesized through the facile calcination process under N 2 and Air atmospheres. The ultraviolet‐visible diffuse reflectance spectroscopy (UV‐Vis DRS) analysis and Density Functional Theory (DFT) calculation results confirm that the bandgap reduces along with the increment of the oxygen vacancy content. The CoMoO 4 ‐N 2 with higher oxygen vacancy concentration exhibits more superior electrochemical performance than CoMoO 4 ‐Air, which delivers an ultrahigh specific capacity (999 mA h g −1 after 500 cycles at 0.5 A g −1 ), remarkable rate capacity (477 mA h g −1 at 9 A g −1 ), and excellent cycling stability (650 mA h g −1 after 1000 cycles at 2 A g −1 ).