Template-Free Synthesis of Honeycomblike Porous Carbon Rich in Specific 2-5 nm Mesopores from a Pitch-Based Polymer for a High-Performance Supercapacitor

A template-free strategy has always been attractive to design and fabricate advanced carbon materials with tunable nanostructures from cheap precursors. Herein, honeycomblike mesoporous carbons (HPCs) are prepared from pitch based polymers through a self -assembly foaming strategy without using any templates. Rich mesopores specific in sizes of 2-5 nm and abundant open-ended honeycomblike holes endow a hierarchical pore-in-pore feature of HPCs and an ultrahigh specific surface area (3473 m(2) g(-1)). With their superior structure, HPCs can deliver a high supercapacity of 339 F g(-1) at a current density of 1 A g(-1) in 6 M KOH aqueous electrolyte and retain 85.6% of the capacity even at a current density of 50 A g(-1). Meanwhile, a supercapacitive cell assembled by two HPC electrodes yields a conspicuously ultrahigh energy density of 34.5 Wh kg(-1) (12.8 Wh L-1) at a high power density of 679.4 W kg(-1) (251.4 W L-1). This work provides a new method for the controllable synthesis of advanced carbon materials from pitch and presents further applications in flexible electrochemical supercapacitors.