A Reactive Template Synthesis of Hierarchical Porous Carbon and Its Application to Supercapacitor Electrodes

Abstract

Abstract Hierarchical porous carbons (HPCs) are highly in demand as electrode materials for efficient supercapacitors. Herein, a modified template carbonization approach in conjunction with chemical activation is described for synthesis of HPCs by direct one‐pot pyrolysis of a mixture of glucose (G), reactive template precursor (Zn 2 (OH) 2 CO 3 )(BZC), and K 2 CO 3 (PC) in which in situ ZnO produced from decomposition of Zn 2 (OH) 2 CO 3 acts as template and K 2 CO 3 as activator, followed by simple acid‐leaching. The resultant undoped carbon [HPC(G‐BZC‐PC)] is endowed with coral reef‐like morphology, 3D porous networks, numerous micro/mesopores, ultrahigh surface area, and goodelectrical conductivity. The specific capacitance delivered by a two‐electrode symmetric supercapacitor with the HPC(G‐BZC‐PC) achieves 241.2 F g −1 at 1 A g −1 , which is superior to that of the two control samples prepared without addition of BZC and PC, respectively. Furthermore, the rate capability reaches as high as to 90.5% and 74.6% with current density from 1 to 10 A g −1 and 50 A g −1 , respectively, and an excellent cycling stability is observed with more than 98% of retention after 10 000 cycles at 5 A g −1 in 6 m KOH. It is concluded that a cooperative effect deriving from the above‐mentioned unique features contributes to the enhanced supercapacitor performance.