Fe/Co Double Hydroxide/Oxide Nanoparticles on N-Doped CNTs as Highly Efficient Electrocatalyst for Rechargeable Liquid and Quasi-Solid- State Zinc–Air Batteries

摘要

Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are the cornerstones of rechargeable zinc-air batteries (ZABs). The exploration and rational design of high-performance, durable, and nonprecious metal bifunctional oxygen electrocatalysts is highly desired for the large-scale application of rechargeable ZABs. Herein, an effective and straightforward coupling approach is developed to fabricate high-performance bifunctional ORR/OER electrocatalysts based on novel nanostructured amorphous bimetal Fe/Co hydroxide/oxide nanoparticles (10-20 nm) inlaid on multiwalled N-dopted carbon nanotubes (FeCo-DHO/NCNTs). Fe/Co nanoparticles achieve a maximum contact area on the NCNTs, effectively facilitating the rapid electron transport and preventing the aggregation of nanoparticles. Consequently, the as-prepared FeCo-DHO/NCNTs show a half-wave potential of 0.86 V for ORR and a low operating potential of 1.55 V at 10 mA cm(-2) for OER in 1.0 (M) KOH, superior to most bifunctional oxygen electrocatalysts reported so far. Moreover, the assembled all-solid-state zinc-air batteries with FeCo-DHO/NCNTs catalyst as the air electrode demonstrate remarkable stability over long-term cycling and excellent charging-discharging performance, with a low voltage gap (1.085 V at 60 mA cm(-2)) and high energy efficiency (60% at 10 mA cm(-2)) under ambient conditions.