Ni@PdNiOx Bimetallic Synergism and Oxide Site Modulation to Boost Oxygen Electrocatalysis in Highly Durable Zn-Air Batteries

Recently, zinc-air batteries have been of great interest due to their high theoretical specific energy that plays an important role in renewable energy conversion, while the sluggish kinetics of their half-reactions of oxygen reduction and oxygen evolution (ORR/OER) limit their widespread applications. Herein, we report the synthesis of self-assembly Ni@PdNiO x seashell-like nanostructures (Ni@PdNiO x NSs) with low Pd content through a novel one-step wet chemical method for the first time. The optimized self-assembly Ni@PdNiO x NSs with a thickness of 2.06 nm are connected self-assembled to form a network structure, which exhibits a large surface area and unprecedented ORR/OER with a positive half-wave potential of 0.892 V vs. RHE and an overpotential of 230 mV at 10 mA/cm 2 in alkaline solution, outperforming most of the PdNi catalysts. When the self-assembly Ni@PdNiO x NSs are applied as electrodes for zinc-air batteries, they deliver a high power density of 88.9 mW/cm 2 and an impressive energy density of 714 mA·h·g −1 . This work opens up a new strategy for generating superior oxygen electrocatalysis and provides new insight into the correlation of low Pd content and Ni in the improvement of alkaline oxygen electrocatalysis.