• • CAC-120 delivers a specific capacity of 371.4 mAh g−1 at 1 A g−1, representing a significant improvement over undoped carbon cathodes, which is critical for meeting the energy density demands of commercial ZICs.
• • The material exhibits 90.6% capacity retention (reversibility) and 74% capacity retention after 10,000 cycles, indicating robust long-term stability essential for grid-scale storage applications.
• • DFT calculations identify pyridinic N as the primary active site for Zn2+ adsorption, with adsorption energies ranging from −0.25 to −0.10 eV, providing a mechanistic basis for designing high-capacity carbon cathodes.
• • A full ZIC device using CAC-120 achieves a reversible capacity of 90.8 mAh g−1 at 0.2 A g−1 and maintains stability over 17,000 cycles, demonstrating practical viability for aqueous zinc-based energy storage systems.