Innovative Fabrication of Pd/Pd4S Based Highly Active Electrocatalysts for ORR in a Primary Zn-Air Battery

Abstract

On account of their high theoretical energy density and minimal cost, Zn-air batteries have gotten a lot of interest as a viable energy storage technology. However, the problem of a high overpotential at the cathode because of the slow oxygen reduction reaction (ORR) kinetics persists. Developing an efficient cathode ORR catalyst and exceeding in performance in comparison to the existing and widely utilized Pt-based catalysts is still a formidable challenge. Herein, this study focuses on the design of a Pt-free catalyst, precisely, Pd/Pd4S based electrocatalysts to enhance ORR performance of cathode. The simple encapsulated structure containing nitrogen-doped carbon (N-doped C) coated Pd/Pd4S and CeO2 nanoparticles (Pd-Pd4S/CeO2/N-C) fabricated by a practical and trouble-free approach has a powerful electrochemical ability. Pd-Pd4S/CeO2/N-C displays a virtually identical limited current density to the commercial 20% Pt/C catalysts and better durability under alkaline conditions. Moreover, this work involves the subsequent utilization of Pd-Pd4S/CeO2/N-C in a primary Zn-air battery as the air electrode, where it manifested comparable current density and power density at 0.6 V as furnished by the Pt/C catalyst. Along with this, the primary Zn-air battery system comprising Pd-Pd4S/CeO2/N-C exhibited constant discharge comprising several hours, a specific capacity of 748 mAh gZn −1, and stability at 10 mA cm−2.