(La_0.8Sr_0.2)_0.95Mn_0.5Fe_0.5O₃Perovskite as anEfficient Bi‐Functional Electrocatalyst for Oxygen‐Involved Reaction and Zn‐Air Batteries

Abstract

The perovskite‐type oxide (La0.8Sr0.2)0.95Mn0.5Fe0.5O3, synthesized using lanthanum resources recovered from polishing powder waste and manganese resources obtained from zinc anode mud, was prepared via a facile polymer‐assisted combustion method, and further applied in zinc‐air batteries. The crystal phase and microstructure features of the obtained nanoparticles were characterized usingn (XRD), (SEM), (TEM), (XPS), and nitrogen adsorption‐desorption measurements. The results showed that the obtained (La0.8Sr0.2)0.95Mn0.5Fe0.5O3 nanoparticles, with nanoscale size, possess a high specific surface area and a suitable Mn3+/Mn4+ molar ratio, which will benefit both the(ORR) and the (OER). As expected, the thus‐fabricated (La0.8Sr0.2)0.95Mn0.5Fe0.5O3 electrode exhibits a high current density of 71.2 and 85.2 mA cm‐2 at ‐0.2 V and 0.6 V vs. Hg/HgO, respectively, which is superior to that of the commercial Pt/C catalyst (58 and 31 mA cm‐2, respectively). Subsequently, this compound oxide can be an air electrode in a rechargeable zinc‐air battery. The assembled battery, using (La0.8Sr0.2)0.95Mn0.5Fe0.5O3 as the cathode, exhibits a discharge voltage of 1.05~1.16 V and a charge voltage of 2.03~2.13 V under 15 mA cm‐2 for 150 h. The excellent electrochemical results presented in this study highlight the potential of (La0.8Sr0.2)0.95Mn0.5Fe0.5O3 as a highly efficient and commercially viable bifunctional electrocatalyst for applications in rechargeable zinc‐air batteries.