Quantum mechanics

Power density

Coal tar

Catalysis

tar (computing)

Composite number

Engineering

Capacitance

Mesoporous material

Electrochemistry

Materials science

Power (physics)

Computer science

In situ

Carbon fibers

Chemical engineering

Coal

Porosity

Physical chemistry

Supercapacitor

Physics

Nanotechnology

Organic chemistry

Microsphere

Carbonization

Composite material

Chemistry

Programming language

Scanning electron microscope

Electrode

Current density

Electrolyte

Journal of Colloid and Interface Science

Three-dimension (3D) porous carbon-sheet microspheres (PCSMs) are prepared through coating coal tar pitch on basic zinc carbonate microspheres followed by in situ ZnO template carbonization and KOH activation. The as-prepared PCSMs show microsphere morphology composed of petal-like carbon nanosheets, which have large specific area (1359.88–2059.43 m2 g−1) and multiscale pores (mainly micropores and mesopores). As the supercapacitor electrodes, the 3D PCSMs present a good electrochemical performance with a large specific capacitance of 313 F g−1 at 1 A g−1 and high rate capability of 81.9% capacitance retention when increasing the current density up to 50 A g−1 in a three-electrode system. In addition, the energy density can reach up to 18.79 Wh kg−1 at a high power density of 878.4 W kg−1 for PCSMs-0.2a symmetrical supercapcitor in 1 M Na2SO4 electrolyte.

In-situ ZnO template preparation of coal tar pitch-based porous carbon-sheet microsphere for supercapacitor