Toward high-rate supercapacitor: Preparation of hierarchical porous carbon binder-free electrode with controllable texture

摘要

Hierarchical porous carbon (HPC) as binder-free electrode attracts enormous attention due to its favorable structure, which is advantageous for the improvement of supercapacitor capacitance and rate capability. In this paper, texture controllable HPC binder-free electrode with high capacitive performance is successfully prepared by polymerization induced phase separation method. Solvents with various viscosities and hydroiodic acid with various amounts are used to regulate the texture. The desired hierarchical porous structure endows the carbon material with a high specific surface area and ideal transportation paths. The optimized HPC binder-free electrode reaches a high specific capacitance of 180.6 F g(-1) at 0.2 A g(-1) in a two-electrode configuration in 6 M KOH. Surprisingly, the capacitance of the electrode still remains 79.1% (142.9 F g(-1)) at 100 A g(-1). Furthermore, energy density of the supercapacitor device ranges from 6.27 Wh kg(-1) to 4.23 Wh kg(-1) with the power density ranging from 100 W kg(-1) to 46195 W kg(-1).