Heteroatom-doped ultrahigh specific area carbons from hybrid polymers with promising capacitive performance

Abstract

Development of the high capacitive supercapacitors needs the design of innovative materials that combine high surface area, hierarchical porous structures with doping of appropriate elements to accelerate ion transport and elevated electrolyte permeability. Herein, a series of ultrahigh surface area with intrinsic multiple-heteroatom doped carbon materials with excellent electrochemical performance are prepared via a simple chemical foaming strategy during the pyrolysis process of poly (bisphenoxy)phosphazene (PBPP). Due to the synergistic effect of the self-blowing strategy under pyrolysis, the as-synthesized polyphosphazene carbons (PZCs) exhibit a large number of hierarchical pores with ultrahigh specific surface area (up to 3673 m2 g-1). The ideal pore structures and N, P, O co-doping endue the carbon with a high specific capacitance of 225.0 F g-1 in 6 M KOH at 0.5 A g-1 of symmetric cell. Two methods contain pre-treatment and post-treatment, introducing reduced graphite oxide (rGO) into the precursor and in-situ polymerizing polyaniline (PANI) on the carbon, are used to modify the obtained carbons for further enhancing the capacity. PANI/PZC5-600-3 exhibits two-electrode specific capacitance of 413.1 F g-1 in 1 M H2SO4 at 1 A g-1, which is significantly higher than PZC5-600-3 and PZC5/2%rGO-600-3, with 90% increment compared with PZC5-600-3.