Renewable wood-derived hierarchical porous, N-doped carbon sheet as a robust self-supporting cathodic electrode for zinc-air batteries

Heteroatom doped porous carbon materials have emerged as essential cathode material for metal-air battery systems in the context of soaring demands for clean energy conversion and storage. Herein, a three-dimensional nitrogen-doped carbon self-supported electrode (TNCSE) is fabricated through thermal treatment and acid activation of raw wood. The resulting TNCSE retains the hierarchical porous architecture of parent raw lumber and holds substantial defect sites and doped N sites in the carbon skeleton. Assembled as a cathode in the rechargeable zinc-air battery, the TNCSE exhibits a superior peak power density of 134.02 mW/cm2 and an energy density of 835.92 mAh/g, significantly exceeding the ones reference commercial 20% Pt/C does. More strikingly, a limited performance decay of 1.47% after an ultra long-period (500 h) cycle is also achieved on the TNCSE. This work could offer a green and cost-save approach for rationally converting biomass into a robust self-supporting cathode material for a rechargeable zinc-air battery.