Introduction of hierarchical porous structure and heteroatom in porous carbons are always effective approaches to improve the capacitive performance for supercapacitor. However, it is still a challenge to achieve the desired structure characteristics by a convenient one-step synthesis. Herein, C16mimPF6, an ionic liquid, was introduced in the self-assembly process of poly-benzoxazine to obtain a unique skin-tissue-bone structured hierarchical porous carbon with homogeneous N, P co-doping after carbonization. As the key component, C16mimPF6 works not only as a structure-directing agent to form a hierarchical structure through microphase separation mechanism, thereby promoting the transfer of ion and electron, but also as a heteroatom precursor to contribute an additional pseudocapacitance by doping phosphorus atoms on carbon matrix. The obtained porous carbon displays a high gravimetric capacitance (Cg) of 209 F g-1 (especially in the carbons prepared without corrosive activation step), a good volumetric capacitance (Cv) of 132 F cm-3 and an excellent area-normalized capacitance (Ca) of 35 μF cm-2. Overall, this work opens a new way to design the polymer-derived carbons with easy heteroatoms doping and hierarchical porous structure.
Keywords: Heteroatom doped carbon; Ionic liquid; Microphase separation; Self-assembling; Supercapacitor.
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