Biomass-derived n-doped carbon for electrochemical supercapacitors

The electrochemical supercapacitor is considered a next-generation energy storage device to meet energy requirements because of its higher power density compared with the conventional capacitor and Li-ion batteries. Biomass-derived nitrogen-doped carbon materials have gained significant attention for their application in supercapacitors as prospective electrode materials due to their widespread availability, low cost, environmentally friendliness, renewable character, large surface-to-volume ratios, high electrical conductivity, good surface wettability, and extra pseudocapacitance behavior. In addition to those, varieties of nitrogen-doped carbon materials with different sizes and dimensions, morphologies, and nanostructures have been produced by various methods using biomass as raw materials, giving new and potential opportunities for the development of supercapacitor electrode materials that are both robust and high-performing. Generally, the basic components or elements of biomass materials are carbon, N, S, and phosphorous. The presence of N in the biomass-derived carbon induces more electroactive sites for ion adsorption, ion transport, and redox reactions, increases electrical conductivity, tightens the binding forces between carbon and S, and improves the electrochemical catalytic reactions for energy storage in the supercapacitor. This chapter summarizes the recently reported biomass-derived nitrogen-doped carbon materials with different nanostructures using different synthetic methods and their applications in supercapacitors as electrode materials. In addition, it also describes the existing challenges and future perspectives of N-doped carbon materials based on their supercapacitance performance as electrode materials.