Alkali-Oxygen Batteries Based on Reversible Superoxide Chemistry.

Rechargeable superoxide (O₂¯) batteries have the potential to surpass current lithium-ion technology due to their high theoretical energy densities. The use of superoxide as an energy storage material is highly advantageous when compared to their close relative, peroxide. This is due to enhanced reversibility of the 1-electron redox process. To efficiently stabilize superoxide, larger metal cations are required such as sodium and potassium. Therefore, the two most studied systems are sodium and potassium oxygen batteries. Both batteries present unique advantages and challenges. In this minireview, we summarize the current research for each superoxide-based battery and offer perspective for further research.