Lanthanum strontium cobaltite-based perovskite as an electrocatalyst for zinc-air battery application

Abstract

Developing a low-cost and highly efficient electrocatalyst for bifunctional oxygen electrocatalytic activity is crucial in the field of energy conversion and storage devices. In this study, we employed a doping strategy to finely tune the electronic structure of lanthanum strontium cobaltite-based perovskite. Furthermore, we introduce Mn, Ni, and Cu cations as dopants at the B-site of lanthanum strontium cobaltite, La0.5Sr0.5CoO3 (LSCO), to investigate oxygen electrocatalytic activity in alkaline electrolytes. Among the electrocatalysts we synthesized, La0.5Sr0.5Co0.8Ni0.2O3 (LSCNiO) exhibited the lowest OER overpotential (ηj=10) of 429 mV in 0.1 M KOH, surpassing LSCO by 71 mV and LCO by 204 mV, respectively. Additionally, LSCNiO demonstrated a positive potential of 0.68 V @ 1 mA cm−2 for ORR, which is 50 mV less for LSCO catalyst. The improved electrocatalytic activity was investigated using spectroscopic techniques, confirming the presence of oxygen vacancies and an elevated Co oxidation state. The synergistic interplay between Co and Ni cations enhanced the hybridization between Co/Ni 3d and O 2p bands, reducing energy barriers and improving oxygen reaction kinetics. Finally, LSCNiO oxide with a bifunctional index (ΔE) of 1.08 V is tested for zinc-air battery (ZAB) applications.