Multifunctional Selenium Vacancy Coupling with Interface Engineering Enables High-Stability Li–O₂ Battery

The commercial application of Li–O₂ batteries with ultrahigh energy density hinges on the development of reliable catalysts. Therefore, a well-designed oxygen electrode with superior catalytic activity is critical to enhancing the comprehensive performance of the Li–O₂ cell. Here, the surface electronic structure of NiSe nanorod array is regulated by introducing selenium (Se) vacancy to boost its bifunctional catalytic activity. The introduction of Se vacancy induces the generation of surface topology structure, which helps in creating abundant catalytic sites on the surface and boosting the kinetics of oxygen redox reaction. Furthermore, terrific interfacial interactions between catalyst and substrate and the distinctive three-dimensional (3D) open framework promote the transport of reactants and accelerate the electrochemical reactions. Specifically, the battery based on V_Se-NiSe@NF exhibits a high discharge capacity of 5412 mA h g^–1 and superior cycling stability of over 118 cycles as compared to those of pristine NiSe@NF (67 cycles). This work demonstrates that the regulation of electronic structure and interfacial interactions can significantly increase the electrocatalytic activity of the oxygen electrode and puts forward a reasonable strategy for the development of a high-performance oxygen electrode for Li–O₂ battery.