Ultrahigh Surface Area Hierarchically Porous Carbon Materials from Polyacrylamide-Cellulose Hydrogel for High-Performance Supercapacitors

High surface area, hierarchically micro/mesoporous carbon materials with interconnected pore structures have significant potential as electrode materials for high-performance supercapacitor applications. Here, we present the synthesis of ultrahigh surface area hierarchically porous carbon materials, prepared by potassium carbonate (K2CO3) activation of polyacrylamide-hydroxy propyl cellulose (PAM-HPC) hydrogel at high temperatures (500-900 degrees C), and their energy storage performances in two- and three-electrode cell setup. The carbon material obtained by carbonization of the PAM-HPC hydrogel at 800 degrees C exhibits an ultrahigh surface area of 3387.2 m(2) g(-1) with a large pore volume of 1.963 cm(3) g(-1). The electrode prepared using this material demonstrated excellent supercapacitance performance in the three-electrode system, achieving a high specific capacitance of 545.5 F g(-1) at 1 A g(-1) current density with superior rate capability and an outstanding cycling stability of 96.3% after 5000 charge-discharge cycles. Furthermore, the assembled symmetric supercapacitor device constructed by using this material showed a high specific capacitance of 102.5 F g(-1) at 0.5 A g(-1). It delivers a high energy density of 17.2 W h kg(-1) at the power density of 550 W kg(-1), and a superior cycling stability of 94.2% after 5000 consecutive charge-discharge cycles. The electrochemical properties reported here indicate that hierarchically porous carbons obtained from PAM-HPC hydrogels are promising materials for high-performance supercapacitor applications.