Honeycomb-Like N, P-Codoped Carbon Derived From Waste Poplar Wood as a High-Performance Air Cathode for Rechargeable...

The sluggish kinetics of the oxygen reduction reaction (ORR) at the cathode hinder the development of zinc-air batteries (ZABs). Herein, a nitrogen and phosphorus dual-doped honeycomb-like carbon (K-NPCW-900) derived from waste wood is fabricated to boost oxygen activation efficiency and enhance ZABs performance. Potassium hydroxide-assisted high-temperature pyrolysis converted poplar wood into a three-dimensional honeycomb-like carbon architecture with high microporosity and large specific surface area, exposing active sites and facilitating mass transport. Density functional theory reveals that asymmetric N─C─P sites inject more electrons than N─C into the O₂ antibonding orbitals, elongating O─O bond to 1.53 Å, facilitating O₂ activation. These sites optimize oxygen-intermediate adsorption, shifting the rate-determining step from ^*OOH on N─C to ^*O reduction. K-NPCW-900 exhibits a high half-wave potential of 0.835 V, indicating favorable electrocatalytic performance. The K-NPCW-900-assembled ZABs deliver a high specific capacity of 797.12 mAh g^-1 and stable cycling for 550 h at room temperature. Impressively, the ZABs retain robust cycling at elevated temperatures of 40°C and 60°C, achieving peak power densities of 180.62 and 265.93 mW cm^-2. This work demonstrates a compositional and structural engineering strategy to convert waste woody biomass into value-added carbon electrodes, facilitating sustainable ZABs development.