Defect engineering of electrocatalysts for metal-based battery

To conquer the instability of clean energy, developing high performance energy storage devices is of vital importance. Among them, metal-based battery (such as Metal-air batteries and metal-sulfur batteries) exhibited high potential for application due to their low lost and high energy density. The rational design of electrode materials (catalysts) plays an important role in improving the energy storage efficacy for metal based batteries and promoting the development of renewable energy technology. With the continuous development of energy storage technology and the in-depth exploration of the electrode reaction mechanism, the researchers found that the electrochemical performances of batteries can be significantly improved by modifying the electrode materials through defect engineering. The introduction of defects in the catalytic electrode material can not only adjust the electronic structure of the catalyst and enhance intrinsic activity, but also the defects can provide a large number of unsaturated sites and provide more favorable active centers for improving the electrochemical kinetics. This paper systematically reviews the action mechanism of defect engineering in the electrocatalytic process and the latest progress in energy storage developments. The reaction mechanism of metal-air batteries and metal-sulfur batteries is introduced firstly. Afterward, the types of defects (intrinsic defects, anion vacancy, cation vacancy, lattice distortion, and heteroatomic doping) and their preparation strategies are summarized. Subsequently, with the typical metal-based batteries (Zn-air battery, Li-O2 battery, Li-CO2 battery, Li-S battery, Na-S battery, etc.) as the foothold, the important role of defect engineering in its application is summarized in detail. Finally, the current challenges and development prospects of metal-based batteries are proposed, aiming to broaden the catalytic electrode materials through defect engineering and promote the commercialization process of clean energy storage devices.