Self-Generated Template Assisted Construction of Nitrogen Self-Doped Porous Carbon Nanoframework with Rich Planar Holes for High Energy Density Supercapacitor

Nitrogen-doped porous carbon materials with planar holes not only inherit the structure advantages of porous carbon materials, but also have a unique planar porosity and heteroatomic doping feature, showing enormous interest in the field of energy storage and conversion. Nevertheless, rational and controllable design of honeycomb-like porous carbon materials with rich planar holes remains a tremendous challenge. Herein, we develop a "bottom-up" self-assembly of carbon- and nitrogen-rich conjugated polymer and subsequent potassium ferrate (K2FeO4) facilitated activation, catalysis and self-generated template assisted carbonization strategy to construct nitrogen self-doped honeycomb-like porous carbon nanoframework (NHPC) with rich planar holes. By exploiting the advantages of the integral and interconnected honeycomb-like carbon skeleton and rich planar holes (rapid ion/electron diffusion) and the efficient nitrogen doping (improved wettability), the NHPC possesses high specific capacitance of 288 F g(-1) at 0.5 A g(-1) and outstanding rate performance. In addition, an aqueous symmetric supercapacitor fabricated from NHPC electrodes possesses widened potential window of 2.0 V, high energy density of 23.6 Wh kg(-1) at 500 W kg(-1), as well as excellent electrochemical stability (91.2% capacitance retention after 20,000 cycles).