Highly Graphitized Porous Carbon Microspheres Derived from Copolymer of Glucose and Melamine for Advanced Electrodes

Abstract The N/O co‐doped hierarchical porous graphitized carbon microspheres (N/O‐PCs) are successfully prepared by condensation polymerization of 5‐hydroxymethylfurfural and melamine, and subsequent KOH activation strategy. The obtained carbon materials have a high specific surface area (1685.58 m 2 g –1 ), rich micro‐ and mesopores, and appropriate pore volume (0.828 cm 3 g –1 ). The degree of graphitization for N/O‐PCs is improved because the ratio of I G and I D increases from 0.88 to 1.03. The layer spacing of the lattice plane (002) for the N/O‐PCs is enlarged, facilitating the transmission of electrolyte ions. The high graphitization degree and enlarged layer spacing bring excellent electrical conductivity and wettability for N/O‐PCs as electrode materials. Besides, owing to the higher N (3.59 at%) and O (12.67 at%) content, the N/O‐PCs show excellent specific capacitances of 412 and 284 F g –1 at the current densities of 1 and 10 A g –1 in 2 m H 2 SO 4 aqueous electrolytes, respectively. Outstanding rate performance (200 F g –1 at 50 A g –1 ) and ideal cycle stability (>10 000 cycles) are achieved. Moreover, the N/O‐PCs‐based symmetric supercapacitor exhibits an energy density of 9.6 Wh kg –1 at 100.8 W kg –1 . Thus, the N/O‐PCs provide the potential for high‐performance supercapacitor electrodes.