N‐doping Hierarchical Porosity Carbon from Biowaste for High‐Rate Supercapacitive Application

Abstract

AbstractIn this work, nitrogen‐doped carbon materials with hierarchical porosity were prepared from biowaste of soybean curd residue (SCR) by KOH activation. The morphology, structure and textural properties of the carbon materials are investigated by scanning electron microscopy, transmission electron microscopy, X‐ray photoelectron spectroscopy, X‐ray diffraction, Raman spectroscopy, and N2 absorption‐desorption isotherms, respectively. The products exhibit high specific surface area of 3431 m2 g−1, high nitrogen doping level, outstanding charge storage capacity of 282 F g−1 at the current density of 0.5 A g−1 and good electrochemical stability over 10000 cycles. Moreover, it still retains 200 F g−1 (71 % of its capacitance at 0.5 A g−1) at 20 A g−1. The findings pave the way for improving charge storage capacity of supercapacitors based on activated carbon and provide a new method to transfer biowaste to effective electrode material.