Mechanochemically synthesized RuO2‐doped LaMnO3 perovskites as bifunctional cathodes for rechargeable Zn/air batteries

Herein, we have developed LaMnO 3 (LMO) perovskite‐based electrocatalysts of oxygen reduction and oxygen evolution reactions (ORR and OER) in a basic aqueous solution. Mechanochemical grinding and thermal annealing leads to highly‐pure perovskites as shown by X‐ray diffraction. This methodology also allows doping the LMO perovskite with RuO 2 , thus improving its catalytic activity, especially the oxygen evolution reaction. ORR have been analyzed by rotating ring‐disk electrode (RRDE). Eventually, these catalysts are employed in Zn/air batteries resulting in specific capacity values of 12.76 Ahg −1 at 1 Ag −1 , when LMO‐RuO 2 (LMO−Ru) was used as catalyst in the positive electrodes. Besides, high operational stability of Zn/air batteries for over 100 cycles was obtained, saving 1.46 mWh per cycle when LMO−Ru was used with respect to pure LMO.