2 research outputs found
Activated carbon derived from tree bark biomass with promising material properties for supercapacitors
Activated carbon from tree bark (ACB) has been
synthesized by a facile and environmentally friendly activation
and carbonization process at different temperatures (600,
700 and 800 °C) using potassium hydroxide (KOH) pellets as
an activation agent with different mass loading. The physicochemical
and microstructural characteristics of the as-obtained
material revealed interconnected microporous/mesoporous architecture
with increasing trend in specific surface area (SSA)
as carbonization temperatures rises. The SSA values of up to
1018 m2 g−1 and a high pore volume of 0.67 cm3 g−1 were
obtained. The potential of the ACB material as suitable
supercapacitor electrode was investigated in both a three and
two-electrode configuration in different neutral aqueous electrolytes.
The electrodes exhibited electric double-layer capacitor
(EDLC) behaviour in all electrolytes with the Na2SO4
electrolyte working reversibly in both the negative (−0.80 V
to −0.20 V) and positive (0.0 V to 0.6 V) operating potentials.
A specific capacitance (Cs) of up to 191 F g−1 at a current
density of 1 A g−1 was obtained for the optimized ACB electrode
material in 1 M Na2SO4 electrolyte. A symmetric device
fabricated exhibited specific Cs of 114 F g−1 at 0.3 A g−1 and
excellent stability with a coulombic efficiency of a 100 % after
5000 constant charge–discharge cycles at 5.0 A g−1 and a low
capacitance loss for a floating time of 70 h.The South African Research Chairs Initiative of the Department of Science and Technology, Republic of South Africa and National Research Foundation of South Africa (Grant no. 97994).http://link.springer.com/journal/100082018-03-30hb2016Physic