An universal in‐situ phosphating strategy to fabricate high‐performance Co 2 P‐based bifunctional oxygen electrocatalyst derived from conjugated polyaniline‐phytic acid copolymer

Abstract Electrocatalysts play a crucial role in the performance of rechargeable Zn‐air batteries (ZABs), but it is still difficult to produce nonprecious materials with excellent bifunctional oxygen reduction reactions (ORR) and oxygen evolution reactions (OER). Herein, conjugated polyaniline‐phytic acid polymer (pANI‐PA) was directly calcined to fabricate Co 2 P nanoparticles embedded in N, P‐doped carbon network composites (Co 2 P@pDC‐PA) for metal‐air cathodes. The resulting pANI‐PA derived Co 2 P‐based carbon composite exhibits exceptional bifunctional ORR/OER activities with a half‐wave potential of 0.79 V for ORR and 1.62 V of over‐potential for OER at 10 mA·cm −2 . Owing to the synergistic effect of its unique three‐dimensional (3D) structure, N, P‐doped carbon framework, and encapsulated Co 2 P nanoparticles, as‐fabricated composite can be used as a highly efficient air cathode in the rechargeable metal‐air battery. The assembled rechargeable ZAB demonstrates a high‐power density of 190.0 mW·cm −2 and remarkable cycling stability over 1000 h. This study introduced a novel approach that paves the way for the efficient, cost‐effective, and scalable production of bifunctional electrocatalysts for rechargeable ZABs.