Enhancement in electrochemical performance of nitrogen-doped hierarchical porous carbon-based supercapacitor by optimizing activation temperature

The electrochemical performance of carbon-based supercapacitor is closely related with the microscopic characteristics of electrode materials. Here, nitrogen-doped hierarchical porous carbons (NHPC) was fabricated by KOH treatment and pyrolyzation using pig nail as a protein-rich biomass source, and microscopic characteristics of the materials were effectively tailored by optimizing activation temperature to enhance electrochemical performance of carbonaceous materials for supercapacitor. The results show that the optimum activation temperature is 800 °C. The constructed NHPC-800 displays three-dimensional interconnected honeycomb structure, possesses high specific surface area (2563.30 m2 g−1) with high-speed ion transfer channels. Additionally, NHPC-800 deliver superior capacitance with 251.4 F g−1 at 1 A g−1. Besides, a remarkable energy density of 29.43 Wh kg−1 corresponding to power density of 847.9 W kg−1 is verified by an assembled symmetric supercapacitor in EMIMBF4 electrolyte.