Nitrogen enriched high specific surface area biomass porous carbon: A promising electrode material for supercapacitors

In this report, a hierarchical porous activated carbon material with interconnected micro-meso-macro pores was prepared and studied with biomass waste as the starting point and transformation into high-value materials as the destination. Based on biomass hazelnut shell, a porous carbon material with a large specific surface area (3374 m2 g−1), rich pore structure, and suitable nitrogen content is constructed with polypyrrole as nitrogen source and KOH as the activator. Because of its unique pore structure, large specific surface area, and suitable nitrogen content, the prepared material as supercapacitor electrodes showed excellent capacitive performance (334 F g−1 at 0.5 A g−1), good rate capacity, and cycle stability. The experimental results show that the introduced nitrogen-containing functional groups endow the material with large pseudo-capacitance, which is conducive to increasing the specific capacitance. In addition, the symmetrical supercapacitor devices assembled on the basis of the material also showed excellent performance with an energy density of 11.4 W h kg−1 at a power density of 300.4 W kg−1. This synthetic strategy shows that the preparation of high-value electrode materials from biomass waste is promising.