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 K-3(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.

Automated summary

In this study, porous carbon nanostructures were designed and fabricated, and redox-active species were added to enhance the performance of supercapacitors. The results showed that the prepared material exhibited high specific capacitance and energy density. Furthermore, asymmetrical coin-cell devices were used to further improve the performance.