Enhancement of oxygen reduction reaction catalytic activity via the modified surface of La0.6Sr0.4Co0.2Fe(0.8)O(3-delta) with palladium nanoparticles as cathode for lithium-air battery

Abstract

La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) perovskites have previously emerged as efficient cathode catalysts for various electrochemical devices such as solid oxide fuel cells, due to their superior chemical stability and mixed electron ion conductivity. Recently, LSCFs have been studied as the cathode of lithium air batteries at low temperature due to superior electrocatalytic activity. In the case of low-temperature applications, LSCF exhibits low catalytic activity for the oxygen reduction reaction (ORR), despite its relatively good activity for the oxygen evolution reaction (OER). However, the activity on ORR is still a barrier to LSCF being utilized as a catalyst for low-temperature electrochemical devices such as lithium air battery. In this work, different palladium (Pd) contents were deposited on the LSCF surface to improve its ORR activity as a promising bifunctional catalyst in lithium air batteries. Thus, Pd was modified on the LSCF surface and structural and electrochemical characteristics were evaluated. Pd nanostructure can be successfully deposited on the LSCF surface, and the ORR catalytic activity was improved. Furthermore, the capacity in lithium air batteries is 4467 mA h and the cycling performance is improved using optimized LSCF with 20 wt % Pd as potential bifunctionalistic cathode materials. The present results show that the deposition of Pd is an effective approach to enhance the ORR activity of perovskite LSCF.