Air Electrode for the Lithium-Air Batteries: Materials and Structure Designs

The lithium-air battery, considered to be a promising candidate for future applications such as electric vehicles and energy storage, has captured worldwide attention recently because of its superhigh specific energy density even rivaling that of gasoline. This Review covers the most recent and significant scientific progress made in the fields relevant to Li-air batteries, with emphasis on the structure design of air electrodes. After a brief introduction to the operation principles and cathode electrochemical reactions, a discussion of the design and optimization of the cathode structure is presented sequentially, and the final conclusion remarks on future challenges and perspectives. The aim is to provide a better understanding of the effect of the cathode structure on the performance of the promising metal-air battery technologies, and to consider their challenges and perspectives in the future.