Self‐Catalysis‐Graphitization Strategy Toward Coal‐Derived Graphitic Hierarchical Porous Carbon with Advanced Zn‐Ion Storage Capability and Ultrastability

Abstract Based on dual carbon targets, it is a clean and efficient utilization to convert coal into high value‐added carbon materials for Zn‐ion hybrid supercapacitor (ZIHSC), coupling high energy density of batteries and high power output of supercapacitors. Herein, a one‐step self‐catalysis‐graphitization approach is developed to fabricate N/O/S co‐doped graphitic hierarchical porous carbon from bituminous coal by taking advantages of the intrinsic heteroatoms for self‐doping, the associated minerals for graphization and KOH activation for hierarchical porosity, contributing to abundant entrapments for Zn ²⁺ capture, express transfer pathway for fast kinetics and sturdy skeleton for long‐term duration and thereby endowing the coin‐type ZIHSC device an ultrahigh capacity of 229.8 mAh g ⁻¹ at 0.1 A g ⁻¹ with 110.7 mAh g ⁻¹ conservation even at a 500‐fold amplified current density, the maximum energy density of 183.2 Wh kg ⁻¹ and an outstanding stability of 99.3% over 100,000 cycles at 50 A g ⁻¹ . Gratifyingly, the soft‐pack ZIHSC device still delivered a capacity of 141.2 mAh g ⁻¹ at 0.1 A g ⁻¹ and a energy density of 112.3 Wh kg ⁻¹ for practicability. The quasi‐solid ZIHSC device also displayed a capacity of 144.7 mAh g ⁻¹ at 0.1 A g ⁻¹ with a energy density of 115.2 Wh kg ⁻¹ plus excellent mechanical flexibility.