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The N, S dual-doped porous graphitic carbon materials with the high graphitization degree were synthesized from the light fraction of coal tar pitch and waste sponge through a facile "killing two birds with one stone" process. The suitable N and S doping not only can provide extra electroactive sites, but also can improve the storage capacity of Zn ions through the decrease in E a value for LC-750 cathode. [Display omitted] • The N, S dual-doped porous graphitic carbon is prepared via a "killing two birds with one stone" strategy. • The LC-750 exhibits superior pore structures and high graphitization degree. • The LC-750 cathode shows high capacity and excellent performance in AZICs. • The N and S incorporation enhances the Zn2+ adsorption ability and charge transfer behavior. Emerging aqueous zinc–ion hybrid capacitors (AZICs) are considered a promising energy storage because of their superior electrochemical performance. The pore structure, suitable heteroatom content, and graphitization degree (GD) of carbon-based cathodes significantly influence the electrochemical performance of AZICs. The N, S dual-doped porous graphitic carbon materials (LC-750) with the combined characteristics of high GD (1.11) and large specific surface area (1678.38 m2 g−1) are successfully developed by a facile "killing two birds with one stone" strategy using K 3 Fe(C 2 O 4) 3 ·3H 2 O as the activating and graphitizing agent, and waste sponge (WS) and coal tar pitch (CTP) as the heteroatom and carbon resource, respectively. Results show that the LC-750 cathode displays high capacities of 185.3 and 95.2 mAh g−1 at 0.2 and 10 A g−1. Specifically, the assembled LC-750//Zn capacitor can offer a maximal energy density of 119.5 Wh kg−1, a power density of 20.3 kW kg−1, and a capacity retention of 87.8% after 15,000 cycles at 10 A g−1. Density functional theory simulations demonstrate that N and S dual-doping can promote the adsorption kinetics of Zn ions. This design strategy is a feasible and cost-effective method for the preparation of dual heteroatom-doped graphitic carbon electrodes, which enables recycling of WS and CTP into high-valued products. [ABSTRACT FROM AUTHOR]

The dual-ion (B and F) co-doped hierarchical porous carbon with suitable pore size and interconnected network was prepared by a facile activated strategy. The synergistic effect of B and F adsorption and the coupling mechanism between suitable pore size and vacancy defects not only can enhance Zn2+ storage capability but also effectively facilitate electron and ion transfer behavior in porous carbon materials. This work provides a comprehensive illustration and new insights for the rational design of heteroatom-doped porous carbon materials cathode, thereby offering promising potential for practical applications in electrochemical energy storage devices. [Display omitted] • The B/F groups anchored into the hierarchically porous carbon cathode was obtained. • The synergistic effect on dual-ion adsorption enhances the Zn2+ storage capability. • The energy density of 175.8 Wh kg−1 at a power density of 159.1 W kg−1 is achieved. • BFPC-2//Zn delivers a superior capacity retention of 96.9% after 20,000 cycles. Aqueous zinc-ion capacitors (AZICs) are considered potential energy storage devices thanks to their ultrahigh power density, high safety, and extended cycling life. Carbon-based materials widely used as cathodes in AZICs face challenges, such as inappropriate pore sizes, poor electrolyte–electrode wettability, and insufficient vacancy defects and active sites. These limitations hinder efficient energy storage capacity and long-term stability. To address these issues, the B and F co-doped hierarchical porous carbon cathode materials (BFPC) are constructed through a facile annealing treatment process. The BFPC-2//Zn device exhibited high capacities of 222.4 and 118.3 mAh g−1 at current densities of 0.2 and 10 A g−1, respectively. Notably, the BFPC-2//Zn device demonstrated long-term cycling stability with a high capacity retention of 96.9 % after 20,000 cycles at 10 A g−1. Additionally, the assembled BFPC-2 based AZICs displayed a maximum energy density of 175.8 Wh kg−1 and an ultrahigh power density of 17.3 kW kg−1. Mechanism studies revealed that the exceptional energy storage ability and charge-transfer process of the BFPC cathode are attributed to the synergistic effect of B and F heteroatoms and the coupling effect between vacancy defects and pore size. This work presents a novel design strategy by incorporating B and F active sites into hierarchical porous carbon materials, providing enhanced energy storage capabilities for practical application in AZICs. [ABSTRACT FROM AUTHOR]