Rare‐Metal‐Free Redox‐Mediated Zn–Air Rechargeable Battery (ReZARB): A Redox‐Mediated Approach for Reducing Charging Overpotentials

In this paper, a rare‐metal‐free three‐electrode‐type Zn–air/Zn–hydroquinone (HQ) electrochemical cell employing a rare‐metal‐free oxygen reduction reaction catalyst on a discharge electrode and HQ as a redox mediator in the electrolyte in a charging cell electrolyte is demonstrated. We named this as Redox‐mediated Zinc–Air Rechargeable Battery (ReZARB). This newly designed rechargeable battery cell can realize significantly reduced charge–discharge overpotential compared to conventional Zn–air battery systems. Effect of pH and charge–discharge properties is discussed. Also, durability of the ReZARB was examined by charge–discharge cycling test for 100 h.