Effect of nitrogen content on performance of supercapacitors composed of nitrogen-carbon materials

Abstract

Nitrogen-carbon (N-C) materials are emerging as strong contenders to elemental carbon in advanced energy applications. Here we have established a correlation between the nitrogen content and supercapacitor performance in N-C materials. The core concept is that the functionalities of such materials are strongly influenced by the fraction, distribution and chemical configuration of nitrogen in the carbon network.The investigation is carried out on a graphitic carbon nitride (g-CN), from which nitrogen is gradually removed to produce N-C materials having N/C ratios between 0.52 to 0.10. Material with a N/C of 0.15 exhibits the highest capacitance, achieving 77.78 F/g at a current density of 1 A/g. These findings are particularly relevant to g-CN-derived disordered and non-graphitizing carbon systems but are also applicable to other forms of carbon. Precisely tuning the nitrogen content can guide targeted material synthesis and enable first-principles evaluation of an N-C material's suitability for supercapacitor applications.