Coal tar

Catalysis

Raman spectroscopy

Adsorption

Dielectric spectroscopy

Composite number

Engineering

Capacitance

Electrochemistry

Materials science

Cyclic voltammetry

Carbon fibers

Chemical engineering

Coal

Porosity

Physical chemistry

Waste management

Supercapacitor

Physics

Organic chemistry

Optics

X-ray photoelectron spectroscopy

Composite material

Horizontal scan rate

Chemistry

Electrode

Electrolyte

Specific surface area

New Carbon Materials

Porous carbons (PCs) for supercapacitors were synthesized by a combined Mg(OH)2 templating and in-situ KOH activation method using coal tar pitch as the carbon precursor, and were characterized by TEM, Raman spectroscopy, XPS and N2 adsorption. Their electrochemical properties were investigated by galvanostatic charge-discharge, electrochemical impedance spectroscopy and cyclic voltammetry. Results show that the specific surface area of the PCs increases with the KOH dosage and exhibits a maximum with an activation temperature at 800 °C. The optimum PC has a high surface area up to 3 145 m2 g−1 with abundant micropores, and exhibits a high specific capacitance of 272 F·g−1 at 0.05 A·g−1, a rate capability of 217 F·g−1 at 20 A·g−1 and a good cycle stability with a 96.69% capacitance retention after 10000 cycles in a 6 mol/L KOH electrolyte. This work provides a simple method for the large-scale production of PCs from pitch-based carbon sources for high-performance supercapacitors.

Synthesis of porous carbons from coal tar pitch for high-performance supercapacitors