The preparation of 3D network pore structure activated carbon as an electrode material for supercapacitors with long-term cycle stability

The high performance bio-based activated carbon (BAC) was prepared via a novel combination of chemical and physical activation processes using coconut shells as a precursor. The as-obtained BAC exhibited a three-dimensional (3D) network pore structure, high specific surface area (3242.05 m(2) g(-1)), unobstructed and interconnected pores, and large pore volume (1.919 cm(3) g(-1)). The BAC exhibited a high specific capacitance of 337 F g(-1) (202 F cm(-3)) and retained a specific capacitance of 331 F g(-1) (190 F cm(-3)) after 10 000 cycles (98% capacitance reservation) at a current density of 0.5 A g(-1) in a 6 M KOH electrolyte. AC-W had a gravimetric capacitance value of 240 F g(-1) and a volumetric capacitance value of 120 F cm(-3) in 1 M TEA BF4/AN. The BAC shows ideal properties as electrode material and also exhibits long-term cycle stability, low capacitance loss rate and high capacitance as an electrode material in aqueous and organic electrolytes. These results are expected to develop efficient, environmentally friendly and low-cost supercapacitors, as well as to promote their application in future electric vehicles, mobile phones and power electronics.