Polymerization-Pyrolysis Assisted Construction of Multiscale Porous Carbon for High-Performance Supercapacitors

High energy density combined with rapid mass transport is highly desired for carbon-based electrical double-layer capacitors. Here, multiscale porous carbon has been constructed by an efficient polymerization-pyrolysis strategy. The resorcinol-formaldehyde polymer anchored with Fe 3+ is firstly prepared, and the in situ formed Fe 3 O 4 nanoparticles act as mesoporous template during the pyrolysis process. The resultant hierarchically porous carbon achieves an extended surface area of 2260.3 m 2 g −1 and wide pore size distributions including micro-, meso-, and macropores. The synergism of large surface area, high conductivity, and interconnected ion transport channels leads to superior energy storage performances of prepared multiscale porous carbon electrode. It delivers a high specific capacitance of 271.7 F g −1 at 0.5 A g −1 in KOH electrolyte, accompanied with a prominent capacitance retention of 88.5% when the current density is 10.0 A g −1 . Besides, the assembled symmetric supercapacitor using organic electrolyte exhibits a maximum energy density of 54.0 Wh kg −1 at the power density of 750.0 W kg −1 , as well as the superior cyclic stability with a capacitance retention of 88.2% after 10000 cycles.