A Continuous Carbon Nitride Polyhedron Assembly for High-Performance Flexible Supercapacitors

Flexible supercapacitors with high power density, flexibility, and durability have shown enormous potential for smart electronics. Here, a continuous graphitic carbon nitride polyhedron assembly for flexible supercapacitor that is prepared by pyrolysis of carbon nanotubes wired zeolitic imidazolate framework-8 (ZIF-8) composites under nitrogen is reported. It exhibits a high specific capacitance of 426 F g−1 at current density of 1 A g−1 in 1 m H2SO4 and excellent stability over 10 000 cycles. The remarkable performance results from the continuous hierarchical structure with average pore size of 2.5 nm, high nitrogen-doping level (17.82%), and large specific surface area (920 m2 g−1). Furthermore, a flexible supercapacitor is developed by constructing the assembly with interpenetrating polymer network electrolyte. Stemming from the synergistic effect of high-performance electrode and highly ion-conductive electrolyte, superior energy density of 59.40 Wh kg−1 at 1 A g−1 is achieved. The device maintains a stable energy supply under cyclic deformations, showing wide application in flexible and even wearable conditions. The work paves a new way for designing pliable electrode with excellent electronic and mechanic property for long-lived flexible energy storage devices.