Magnesium-air batteries: from principle to application

Metal-air batteries are important power sources for electronics and vehicles because of their remarkable high theoretical energy density and low cost. In this paper, we introduce the fundamental principles and applications of Mg-air batteries. Recent progress in Mg or Mg alloys as anode materials and typical classes of air cathode catalysts for Mg-air batteries are reviewed. In the meantime, different compositions of the electrolyte are also compared. The design of electrode materials both for anodes and cathodes of Mg-air batteries is discussed for further performance improvement. It is noted that in the development of rechargeable Mg-air batteries, bi-functional catalysts with reversible oxygen reduction and evolution reactions are facing challenges and it is worthwhile devoting much effort to this.