An Exceptionally Facile Synthesis of Highly Efficient Oxygen Evolution Electrodes for Zinc-Oxygen Batteries.

Zinc-oxygen batteries are promising candidates for electrical vehicles and electric grid energy storage due to their low cost, high safety levels, and low environmental impact. The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) represent the most significant processes in zinc-oxygen batteries. The development of nonprecious metal catalysts for OER with satisfactory performances and low cost (especially prepared by a straightforward synthesis route), still poses a significant challenge. Herein, we report an exceptionally facile and easily scalable method to produce NiFe layered double hydroxide (LDH) coated nickel foam by immersing nickel foams into aqueous solutions containing NiCl₂ and FeCl₂ and keeping them standing for a certain period of time. Without any other complicated technique or organic reagent, microflower-shaped NiFe LDHs can be obtained. The resulting electrode shows excellent OER performance with a low overpotential of 210 mV at a 10 mA cm⁻² constant current polarization and stable operation for more than 100 charge-discharge cycles in zinc-oxygen batteries. [ABSTRACT FROM AUTHOR]