Rechargeable Zinc–Air versus Lithium–Air Battery: from Fundamental Promises Toward Technological Potentials

As battery technologies that can potentially increase the energy density and expand application scenarios of the lithium‐ion batteries, rechargeable metal‒air batteries have attracted extensive research interests. Among a variety types of metal anodes investigated, zinc (Zn)‒air and lithium (Li)‒air batteries hold best prospects for real‐world applications and attract the most scientific community interests. It has been more than 10 years since Cho et al. first compared Li–air and Zn–air batteries, during which great progress has been made. In this review, these two representative metal‒air battery technologies are compared in view of the most recent progresses and improvements in the last decade, especially efforts that push these technologies toward real world applications. It starts with the fundamentals of Zn–air and Li–air batteries, and discusses the progress made in electrolyte design, anode protection, and cathode catalysts development. It ends with an evaluation of the current research state along with an overall future perspective. Such a comprehensive comparison of typical non‐aqueous and aqueous battery systems with a focus on practical application criteria would be a timely review of metal‒air battery development in the last decade, which shed light for fundamental and applied research, eventually leading to real‐world application. Zn–air and Li–air batteries are two typical metal‒air battery technologies that hold great prospects toward real‐world application. This review summarizes the challenges and recent advances of the two batteries and evaluates their current commercialization status. Future research direction and application are also discussed.