Microwave-Induced Rapid Synthesis of High-EntropyOxide/Carbon Nanotube Composites for High-Performance Bifunctional Oxygen Catalysis in Zinc–Air Batteries

The fabrication of efficient, low-cost, and stable bifunctional oxygen catalysts is crucial for zinc–air batteries (ZABs). High-entropy materials have emerged to possess great potential as oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) bifunctional catalysts for ZABs, but its efficient synthesis with superior activity remains challenging. Herein, a rapid and facile microwave-induced carbon thermal shock technique was developed to efficiently synthesize high-entropy oxide (HEO) nanoparticles, i.e., (FeCoNiCrMn)₃O₄, that are uniformly anchored onto carbon nanotubes (CNT), denoted as (FeCoNiCrMn)₃O₄/CNT. The obtained (FeCoNiCrMn)₃O₄/CNT can work as a bifunctional catalyst, exhibiting excellent performance with the OER overpotential of 273 mV at 10 mA cm⁻² and the ORR half-wave potential of 0.771 V. Moreover, the ZAB assembled with (FeCoNiCrMn)₃O₄/CNT as the cathode demonstrates superior performance, with high specific capacity (828.8 mAh g_Zn⁻¹), energy density (986.3 Wh kg_Zn⁻¹), and outstanding long-term durability exceeding 500 h. This work offers a scalable strategy in efficient construction of CNT-supported HEO nanomaterials, thus facilitating the development of high-efficiency electrocatalysts for practical ZAB applications.