Electronic Reconfiguration of Co2P Induced by Cu Doping Enhancing Oxygen Reduction Reaction Activity in Zinc–Air Batteries
Developing high efficient and low-cost bifunctional electrocatalysts towards oxygen reduction reaction (ORR) is the core of Zn-air batteries (ZABs) but still a challenge. In this work, electronic reconfiguration and structural optimization are simultaneously conducted to enhance oxygen reduction reaction (ORR) electrocatalytic activity of Co2P nanoparticles, which were doped with Cu as well as confined within 2D ultrathin N, P-codoped carbon (NPC) nanosheets. Density Functional Theory calculations reveal that the doping of Cu can lead to more positive sites on the neighbouring Co site as well as weaken the binding force between the surface active sites and the adsorbed intermediates, while the 2D ultrathin nanosheets with Cu doped Co2P nanoparticles tightly anchored can remarkably boost the surface exposure of actives sites endowing such architecture with efficient mass and charge transport pathways. As expected, the optimized Cu doped Co2P on 2D ultrathin N, P-codoped carbon (Cu-Co2P@2D-NPC) with 7.1%Cu dopping exhibits a higher half-wave potential of 0.835 V than that of Pt/C (0.830 V). Meanwhile, the flexible solid state ZABs assembled based on the 7.1%Cu-Co2P@2D-NPC hybrid delivers a high power density of 52.5 mW cm−2 and 32 h stability during the flat and folded states. This promising work holds significant potential to fabricate efficient electrocatalyst for flexible solid state ZABs and further understand the relationship between structure and activity.