Metal–air batteries: A review on current status and future applications

Metal–air batteries (MABs) have been paid much more attention owing to their greater energy density than the most advanced lithium-ion batteries (LIBs). Rechargeable MABs are considered as promising candidates for the next-generation of energy storage techniques for applications ranging from large-scale energy storage systems to electric vehicles and portable devices. However, there are still numerous scientific problems that must be overcome before their commercial application. With the aim of providing a comprehensive understanding of this new electrochemical system particularly Li–air batteries, this review paper provides an overview of the current status including corresponding strategies from the perspective of various battery components, including air cathode, metal anode and electrolyte. In addition, other promising MABs such as Zn–air, Mg–air and Al–air batteries are also introduced briefly for comparison. Finally, the applications and prospects of these four types of MABs are discussed and some perspectives for this research field are also provided.