FeNiCrCoMn High-Entropy Alloy Nanoparticles Loaded on Carbon Nanotubes as Bifunctional Oxygen Catalysts for Rechargeable Zinc-Air Batteries

An efficient and stable bifunctional oxygen catalystis necessaryto complete the application of the rechargeable zinc-air battery.Herein, an economical and convenient process was adopted to successfullycoat high-entropy alloy Fe12Ni23Cr10Co55-x Mn x nanoparticles on carbon nanotubes (CNTs). In 0.1 M KOH solution,with a bifunctional oxygen overpotential (& UDelta;E) of only 0.7 V, the catalyst Fe12Ni23Cr10Co30Mn25/CNT exhibits excellent bifunctionaloxygen catalytic performance, exceeding most catalysts reported sofar. In addition, the air electrode assembled with this catalyst exhibitshigh specific capacity (760 mA h g(-1)) and energydensity (865.5 W h kg(-1)) in a liquid zinc-air battery,with a long-term cycle stability over 256 h. The density functionaltheory calculation points out that changing the atomic ratio of Co/Mncan change the adsorption energy of the oxygen intermediate (*OOH),which allows the ORR catalytic process to be accelerated in the alkalineenvironment, thereby increasing the ORR catalytic activity. This articlehas important implications for the progress of commercially availablebifunctional oxygen catalysts and their applications in zinc-air batteries.