Self-sacrificing template-derived N/O-doped porous carbons: Exceptional capacitor performance across environmental extremes.

Heteroatom-doped porous carbon exhibit promising potential as supercapacitor electrodes, but the tradeoff between specific surface area (SSA) and heteroatom-doped level limits its excellent performance. In this work, the activation coupled with doping strategy to synthesize the pitch-based porous carbon (PPC). Different from single activation method to prepare microporous carbon, the PPC prepared by the coupling method has a hierarchical porous structure and high SSA (2020 m/g). Melamine acts as a self-sacrificing template, simultaneously realizing N and O dopings and cooperating with KOH to form hierarchical micro-mesopores, which enhance outstanding hydrophilicity. Attributed to the synergistic effect of activation mechanism and doping, PPC shows compatibility of different electrolyte systems and excellent high loading characteristics (220 F/g at 10 mg cm). In addition, the capacitance fluctuation is very small in extreme cases (0 to -40 °C), reflecting the excellent low-temperature performance. Therefore, the porous carbon prepared by the coupling method has a good micro-mesoporous structure and excellent electrochemical properties, which provides a new perspective for the high value-added utilization of low-cost pitch in supercapacitors.