High-yield synthesis of N-rich polymer-derived porous carbon with nanorod-like structure and ultrahigh N-doped content for high-performance supercapacitors

[Display omitted] •N-Doped carbon nanorod was synthesized for supercapacitor electrode materials.•These nanorods exhibit ultrahigh N-doping and large surface area.•The optimized nanorod electrodes deliver attractive electrochemical performance.•Remarkable specific capacitance and cycle stability were demonstrated. Porous carbon with unique nanostructure, high heteroatom doping as well as large specific surface area is regarded as an attractive candidate for supercapacitor applications, yet high-yield and free-template synthesis of such material remains a great challenge. Herein, a facile free-template activation method is adopted to transform a nanorod-like N-rich polymer into a new type of N-doped porous carbon by activation of copper chloride (CuCl2). Utilizing this mild activation agent to fulfill one-step carbonization/activation not only can maintain the natural morphology of the precursor and reduce the release of heteroatoms, but also can achieve high-yield synthesis of N-doped porous carbon with abundant micropores. Moreover, these polymer-derived carbons (C-CuCl2) exhibit an unique nanorod-like morphology with hierarchical porous structures, large surface areas (up to 2167.2 m2 g−1), extraordinarily high N doping level (up to 12.9 wt%), and high carbon yields (up to 60 wt%). Owing to these unique characteristics, the best-performed C-CuCl2-800 exhibits a good electrochemical performacne in supercapacitor applications, delivering a delightful capacitance of 271 F g−1 at 0.5 A g−1 and 97% capacitance retention after 10 000 charge-discharge operations at 5.0 A g−1 in a 6.0 M KOH electrolyte. Moreover, a high energy density of 64.5 Wh kg−1 at 350 W kg−1 is also demonstrated for the ionic-liquid-based supercapacitor. Therefore, the facile activation method offers a promising prospect for the high-yield translation of various polymers into porous carbon nanomaterials with high heteroatom doping and large specific surface area.