Approaches to construct high-performance Mg-air batteries: from mechanism to materials design

Magnesium-air (Mg-air) batteries exhibit very high theoretical energy output and represent an attractive power source for next-generation electronics and smart grid energy storage. In this review, the fundamental principles in the electrochemical reactions of Mg-air batteries are introduced, mainly focusing on the negative corrosion and positive catalytic mechanisms as well as their influence on electrode design. Then, a series of representative electrode materials are reviewed, from materials chemistry to electrode performance. Among these, the main points are to address the challenges faced by Mg-air batteries through electrode material design. Finally, the challenges in the development of Mg-air batteries and the prospects of research directions are presented. The outline of the energy delivery mechanism and strategies for materials construction can serve as a guide for the evolution of high-performance batteries.