Boosting rate capability of ionic liquid supercapacitors by copolymer-derived activated hollow carbon nanospheres

Herein, a novel activated hollow carbon nanospheres (AHCNSs) with enlarged specific surface area (SSA) of 1796 m(2).g(-1) and pore volume (V-p) of 1.33 cm(3).g(-1) was synthesized from poly(aniline-co-pyrrole) hollow nanospheres via KOH activation method. The supercapacitor containing AHCNSs displayed high gravimetric capacitance (C-g) of 290 F.g(-1) at 1 A.g(-1) and 79% capacitance retention even at 20 A.g(-1) in ionic liquid EMIMBF4, indicating its excellent rate capability. This study highlights the potential value of novel hollow structure activated carbon in the field of energy storage.