Catalytic performance of oxygen vacancies-enriched h-MoO₃ in lithium-oxygen batteries

The development of lithium-oxygen battery was an effective way to alleviate energy crisis, save energy and protect environment. The design of cathode catalyst with high catalytic performance can effectively promote the performance of lithium-oxygen battery. To research the influence of oxygen vacancies on the electrochemical catalytic performance, a novel and effective method was proposed to introduce more oxygen vacancies into MoO₃. The h-MoO₃ with oxygen-rich vacancies (named MoO₃-HTP) was synthesized by using original MoO₃ to heat together with NaH₂PO₄. As the cathode catalyst of lithium-oxygen batteries, MoO₃-HTP had a smaller first cycle overpotential of 0.76 V and showed 137 stable cycles under a limited capacity of 500 mAh g⁻¹ at 200 mA g⁻¹ from the comparison of the MoO₃ and MoO₃-HT. And MoO₃-HTP-based batteries had the lower overpotential of 1.58 V under the first full charge-discharge curves at 200 mA g⁻¹ and 400 mA g⁻¹. The excellent conductivity and electrocatalytic performance of MoO₃-HTP were put down to the abundance of oxygen vacancies.