Hierarchical nitrogen-doped porous carbon with high surface area derived from endothelium corneum gigeriae galli for high-performance supercapacitor

Endothelium corneum gigeriae galli derived 3D hierarchical nitrogen-doped porous carbon was for the first time prepared by preliminary carbonization at 450 °C and final KOH activation at high temperatures. The surface and structural properties of the as-synthesized samples are analyzed with Brunauer-Emmett-Teller surface analyzer apparatus, X-Ray Diffractometer, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectrometer. The electrochemical performances are analyzed by cyclic voltammetry, galvanostatic charge/discharge cycling and electrochemical impedance spectroscopy. The obtained results show that the sample carbonized at 900 °C possesses the SSA of 2149.9 m² g^-1, average micropore diameter of 1.78 nm, and exhibits the highest initial specific capacitance of 198.0 F g^-1 at current density of 1 A g^-1 in 6 M KOH solution. It retains good specific capacitance retention of 91.6% after 3000 charge/discharge cycles at current density of 2 A g^-1.