材料期刊网

The double-activated porous carbons (DAPCs)with unique bimodal pore structure were prepared by activating commercial microporous carbon (CMCs) twice through KOH (double activation) at high temperature.The as-prepared DAPCs show larger surface area (833 m2.g-1),and the pores are composed of micropores (size of ～ 1.8 nm) and mesopores (size of ～4.5 nm).Such special hierarchical porous structures integrate the dual advantages of micropore and mesopore,having not only the high energy storage of the micropores but also the high-rate performance of the mesopores for supercapacitors (SCs).As a result,the optimized DAPCs-3-1 exhibits a high specific capacitance of 277 F·g-1 at 1 A.g-1,enhanced rate performance of 197 F.g-1 at a high current density of 10 A.g-1,and excellent cycling stability with 94.2％ capacity retention after 10,000 cycles in the 1 mol.L-1 Na2SO4 electrolyte.The facile double activation could be a promising method to prepare suitable porous carbons with exceptional electrochemical properties for SCs.