Atomic Insights of Iron Doping in Nickel Hydroxide Nanosheets for Enhanced Oxygen Catalysis to Boost Broad Temperature Workable Zinc−Air Batteries

Abstract

Abstract Exploring robust and low‐cost bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) electrocatalysts is of great importance for zinc−air batteries (ZABs). Here, we report a controllable Fe‐doping strategy to promote OER/ORR catalytic performance of Ni(OH) 2 . The results reveal that Ni 1‐x Fe x (x=0, 0.05, 0.1, 0.15, 0.2, and 0.25) hydroxide nanosheets (NSs) display a volcano‐like OER performance, with Ni 0.8 Fe 0.2 NSs being the most optimal OER catalyst, showing an overpotential of 250 mV at 20 mA cm −2 and excellent stability in 1 M KOH. Compared with pristine Ni(OH) 2 NSs, the enhanced OER/ORR performance of Ni 0.8 Fe 0.2 NSs can be attributed to the much more exposed edge sites and oxygen vacancies. Importantly, the rechargeable ZABs built by Ni 0.8 Fe 0.2 NSs can offer excellent charge‐discharge cycling stability not only under 25 °C, but also both the low temperature (−10 °C) and high temperature (40 °C). The work provide a new way to design highly efficient air‐electrode catalysts with broad working temperature.