Amorphous MnO2 Lamellae Encapsulated Covalent Triazine Polymer‐Derived Multi‐Heteroatoms‐Doped Carbon for ORR/OER Bifunctional Electrocatalysis

Abstract

AbstractThe intelligent construction of non‐noble metal materials that exhibit reversible oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with bifunctional electrocatalytic performance is greatly coveted in the realm of zinc‐air batteries (ZABs). Herein, a crafted structure‐amorphous MnO2 lamellae encapsulated covalent triazine polymer‐derived N, S, P co‐doped carbon sphere (A‐MnO2/NSPC) is designed using a self‐doped pyrolysis coupled with an in situ encapsulation strategy. The customized A‐MnO2/NSPC‐2 demonstrates a superior bifunctional electrocatalytic performance, confirmed by a small ΔE index of 0.64 V for ORR/OER. Experimental investigations, along with density functional theory calculations validate that predesigned amorphous MnO2 surface defects and abundant heteroatom catalytic active sites collectively enhance the oxygen electrocatalytic performance. Impressively, the A‐MnO2/NSPC‐based rechargeable liquid ZABs show a large open‐circuit potential of 1.54 V, an ultrahigh peak power density of 181 mW cm−2, an enormous capacity of 816 mAh g−1, and a remarkable stability for more than 1720 discharging/charging cycles. Additionally, the assembled flexible all‐solid‐state ZABs also demonstrate outstanding cycle stability, surpassing 140 discharging/charging cycles. Therefore, this highly operable synthetic strategy offers substantial understanding in the development of magnificent bifunctional electrocatalysts for various sustainable energy conversions and beyond.