One step, In-situ phosphating construction of encapsulated Co2P and Co3(PO4)2 nanoparticles within 3D reticulated carbon for rechargeable Zn-Air batteries

Abstract As potential candidates to be employed as air anodes in metal-air batteries, transition metal phosphides (TMPs) have received considerable attention due to its excellent electrocatalytic activity. This work presents a straightforward method for efficiently fabricating CoPO-Co₂P@NPC, a three-dimensional (3D) reticulated carbon N, P-doped carbon structure generated from polyaniline-phytic acid polymer, with Co₂P and Co₃(PO₄)₂ nanoparticles implanted on the carbon matrix. The CoPO-Co₂P@NPC demonstrates impressive bifunctional oxygen reduction reactions (ORR)/oxygen evolution reactions (OER) performances. A diffusion-limiting current density of 6.56 mA cm⁻ ², a half-wave potential of 0.80 V, and an overpotential of 1.73 V are detected at 10 mA cm⁻ ². The rechargeable ZAB that has been assembled demonstrates a high-power density of 265 mW cm⁻ ², with excellent cycling stability over 450 hours. The composite based on Co₂P-Co₃(PO₄)₂ demonstrates outstanding bifunctional electrocatalytic performance, which makes it a desirable anode material for rechargeable Zn-Air batteries.