Electrochemical characterizations of LaMO3 (M = Co, Mn, Fe, and Ni) and partially substituted LaNi x M1−x O3 (x = 0.25 or 0.5) for oxygen reduction and evolution in alkaline solution

Abstract

Four transition metals, namely cobalt, iron, manganese, and nickel, were separately combined with lanthanum metal to synthesize LaMO3 (M = Co, Fe, Mn, and Ni) perovskites using a sol–gel method. Electrodes for zinc–air rechargeable batteries were prepared with these perovskites and evaluated in terms of their morphology, crystal structure, electric conductivity, surface area, and particle size distribution. The electrochemical properties of the perovskites were characterized as catalysts of bifunctional electrodes for Hgen reduction reaction and oxygen evolution reaction in alkaline solution. Additionally, partially substituted LaNi x (M1, M2, or M3)1−x O3 (x = 0.25 or 0.5, and M1, 2, 3 = Co, Fe, Mn) perovskites were synthesized to evaluate the effect of partial substitution of a metal in the Ni site, and improved physical and electrochemical properties were obtained.