Microwave‐Assisted Synthesis of Highly Active Single‐Atom Fe/N/C Catalysts for High‐Performance Aqueous and Flexible All‐Solid‐State Zn‐Air Batteries

Abstract The development of low‐cost single‐atom electrocatalysts for oxygen reduction reaction (ORR) is highly desired but remains a grand challenge. Superior to the conventional techniques, a microwave‐assisted strategy is reported for rapid production of high‐quality Fe/N/C single‐atom catalysts (SACs) with profoundly enhanced reaction rate and remarkably reduced energy consumption. The as‐synthesized catalysts exhibit an excellent ORR performance with a positive half‐wave potential up to 0.90 V, a high turnover frequency of 0.76 s⁻¹, as well as a satisfied stability with a lost half‐wave potential of just 27 mV over 9000 cycles (much better than that of Pt/C with 107 mV lost) and good methanol resistance. The open‐circuit voltages of as‐constructed aqueous and flexible all‐solid‐state Zn‐air batteries (ZABs) are 1.56 and 1.52 V, respectively, higher than those of 20% Pt/C‐based ones (i.e., 1.43 and 1.38 V, respectively). Impressively, they afford a peak power density of 235 mW cm⁻², which exceeds that of Pt/C (i.e., 186 mW cm⁻²), and is comparable to the best ones of Fe/N/C‐based ZABs ever reported.