P-doped porous carbon derived from walnut shell for zinc ion hybrid capacitors.

Zinc ion hybrid capacitors (ZHCs) are expected to be candidates for large-scale energy storage products due to their high power density and large energy density. Due to their low cost and stability, carbon materials are generally the first choice for the cathode of ZHCs, but they face a challenge in the serious self-discharge behavior. Herein, zinc ion hybrid capacitors with high-performance are successfully assembled using a porous carbon cathode derived from low-cost p-doped waste biomass and a commercial zinc foil anode.