Flower-like MnO2 decorated activated multihole carbon as high-performance asymmetric supercapacitor electrodes

●Simple-but-effective synthetic approach: hydrothermal synthesis without any surfactant.●High specific capacitance: 297.8 F g−1 at 0.2 A g−1.●Excellent cycling stability: 94.8% retention after 1000 cycles at 5 A g−1.●Energy density of 18.04 W h kg−1; maximum power density of 8.97 kW kg−1.

Flower-like MnO2 decorated activated multihole carbon (AMC) was fabricated by a simple but effective strategy. Such unique MnO2@AMC nanocomposite exhibited the optimized pseudocapacitance performance, revealing a specific capacitance (297.8 F g−1) with excellent rate ability. An asymmetric supercapacitor with nanocomposite as the positive electrode and activated graphene (AG) as the negative electrode yielded an energy density of 18.04 W h kg−1 and a maximum power density of 8.97 kW kg−1. And thus, this facile synthetic strategy could be useful to design high-performance electrode for supercapacitors.