Potassium-ion hybrid capacitors (PIHCs) are regarded as one of the promising candidates for large-scale energy storage technologies. Nevertheless, the lack of suitable anode materials combined with fast ion diffusion kinetics and favorable cycle stability restricts their application. Herein, a catalyst-confined graphitization strategy is proposed to synthesize low-cost coal-based carbon anodes, which have controllable heteroatom co-doping and rich defect sites, together with local graphitic domains. Density functional theory calculations and kinetic analysis are performed to uncover the coupling effect for heteroatom dual-doping and defective structures. Importantly, the introduction of graphitic domains ensures good electric conductivity and charge transfer kinetics while preserving rich defects and active sites. The optimized NC-950 exhibits superior potassium storage capacity, which delivers a high reversible specific capacity (363.3 mAh g^-1), impressive rate capability (93.9 mAh g^-1 at 2 A g^-1), and stable cycling performance. As a practical device application, the PIHCs (NC-950//AC) are assembled using the NC-950 anode and commercial activated carbon (AC) cathode, which exhibits the maximum energy density of 97.0 Wh kg^-1 and excellent cycling stability (10 000 cycles). Significantly, this work unveils a new pathway to developing low-cost and fast reaction kinetics carbon anode for advanced electrochemical supercapacitors.