Rechargeable Multi-Valent Metal-Air Batteries A review of research and current challenges in secondary multivalent metal-oxygen batteries

Rechargeable metal-oxygen cells could exceed the stored energy of today's most advanced lithium-ion cells. However challenges exist that must be overcome to bring this technology into practical application. These challenges include, among others, the recharge and cyclability efficiency, materials development and improvements in fundamental understanding of the electrochemistry and chemistry inside the cell. The common challenges for the anode, including corrosion, passivation and dendrite formation and those for the air cathode and the electrolyte are summarised in this review for cells based on magnesium, calcium, aluminium, silicon, zinc and iron.