Doped Lanthanum Nickelates with a Layered Perovskite Structure as Bifunctional Cathode Catalysts for Rechargeable Metal–Air Batteries

Rechargeable metal–air batteries have attracted a great interest in recent years because of their high energy density. The critical challenges facing these technologies include the sluggish kinetics of the oxygen reduction–evolution reactions on a cathode (air electrode). Here, we report doped lanthanum nickelates (La2NiO4) with a layered perovskite structure that serve as efficient bifunctional electrocatalysts for oxygen reduction and evolution in an aqueous alkaline electrolyte. Rechargeable lithium–air and zinc–air batteries assembled with these catalysts exhibit remarkably reduced discharge–charge voltage gaps (improved round-trip efficiency) as well as high stability during cycling.