Symmetric supercapacitor based on lamellar coal pitch-derived mesoporous activated carbon

Abstract

Abstract Mesoporous activated carbon acquired from coal pitch was produced by an elementary activation process utilizing coal pitch, a coproduct of coal tar production, as a precursor material. The activated carbon CP-AC-700 with obvious pore characteristics was obtained by carbonizing the pre-carbonized coal pitch at 700°C with KOH as the activator. The CP-AC-700 exhibited excellent double-layer electrochemical performance in the three-electrode electrochemical testing system. After three-electrode testing, the material had a specific capacitance of 356 F·g− 1 at a current density of 1 A·g− 1. Assembled bilayer supercapacitor was tested in a two-electrode system. At a power density of 500·21 W·kg− 1, the corresponding energy density reached 10.15 Wh·kg− 1. Following 5000 charge/discharge cycles conducted under constant current conditions, the symmetric supercapacitor exhibited a capacity retention rate of 93.02%. Porous activated carbon prepared from coal pitch showed excellent electrochemical properties as a supercapacitor electrode material and proved to be a promising electrode material with double-layer capacitance.