Preparation and electrochemical properties of coke powder activated carbon based electrode materials

Coke powder activated carbons (CPACs) were prepared using coke powder as raw materials. The as-prepared CPACs were characterized by energy dispersive spectrometer, scanning electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The BET surface area and porous properties of CPACs were evaluated by nitrogen adsorption at 77 K. The optimal preparation conditions for CPACs were optimized according to the results of a series of electrochemical performance measurements by using the as-prepared CPACs as electrode in 2 mol L⁻¹ electrolyte solution of KOH. The CPACs, which were prepared under optimal conditions, exhibit a BET surface area of 285.6 m² g⁻¹, a pore volume of 0.112 m³ g⁻¹, a statistical average pore diameter of 10 nm, and ratios of the sum of micro and meso pore volume to the total pore volume of about 80.4 %, respectively. The electrochemical measurement results show that the electrode prepared by CPACs under optimal preparation conditions exhibits a specific capacitance of 211 F g⁻¹. Moreover, it also exhibits a good electrochemical stability with a specific capacitance reaches up to 156 F g⁻¹ over consecutive 1,000 cycle numbers.