Polymer derived honeycomb-like carbon nanostructures for high capacitive supercapacitor application

Scrupulously designed porous carbon nanostructures with high pore volumes and surface area can store a large amount of charge through EDLC behaviour. In this report, polymer-derived honeycomb-like carbon nanostructures (HCNs) have been prepared, taking nano-spherical silica as a template, PVDF as a carbon source, and PMMA as a pore-forming agent. The as-prepared material offers a higher specific capacitance of 578.80 Fg-1 in a basic (6 M KOH) solution. A PVDF/PVP composite membrane has been developed as a separator to fabricate a coin-cell device. The addition of redox-active species [0.1 M K3(Fe(CN)6)3-] with the electrolyte substantially enhanced the supercapacitance properties. The oxidized HCNs (HCNox) have been prepared, and it shows enhanced supercapacitance performance (3328 Fg-1) in redox-active species added 6 M KOH compared to HCNs (913 Fg-1). An asymmetrical coin cell device is fabricated using HCNs as cathode, HCNox as the anode, and PVDF/PVP as separator in redox-active added 6 M KOH. The fabricated asymmetric coin-cell device offers an energy density of 260.18 Wh Kg−1 and a power density of 935.91 W kg−1. The enhanced performance of the supercapacitor device is the concerted effect of HCNs, HCNox, and redox-active added electrolyte, as well as the PVDF/PVP composite separator.