Highly stable Megalopolis lignite based N and S self-doped hierarchically porous activated carbons for high performance supercapacitors and ash content effects on performance

TY - JOUR

T1 - Highly stable Megalopolis lignite based N and S self-doped hierarchically porous activated carbons for high performance supercapacitors and ash content effects on performance

AU - Oglou, Ramadan Chalil

AU - Gokce, Yavuz

AU - Yagmur, Emine

AU - Ghobadi, T. Gamze Ulusoy

AU - Aktas, Zeki

N1 - Funding Information: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. We express our appreciation to Prof Dr M. Sacak and Dr M. K. Erdogan, Dept. of Chemistry, Ankara University, Turkey, for conductivity measurements, and Dr S. Yaglikci, Dept. of Energy Eng. Ankara University, Turkey, for contact angle measurements. Publisher Copyright: © 2021

PY - 2022/2

Y1 - 2022/2

N2 - This study proposes that high value-added activated carbon (AC) is produced from lignite (low rank coal) and used as electrode material in supercapacitors. In addition, the effects of the ash content of the activated carbon on supercapacitor performance are determined. The ACs at a temperature of 800 °C are produced in three different impregnation ratios (IR) (IR: 1, 2 and 4: KOH/precursor) using KOH as the activation agent. While the surface area of ​​the AC produced at IR4 is 2531.4 m2 g−1, it is determined as 1321.3 (IR1) and 1989.0 (IR2) m2 g−1 for the others. The pore size analysis of the samples shows that the mesopores are dominant in the IR1 (52.73%) and IR4 (88.74%) samples, while it is observed that the micropores are dominant in the IR2 (69.03%) sample. The IR4 sample gives excellent results. The cell specific capacitances of this sample are determined as 260.47 F g−1 (at 1 A g−1) and 150.3 F g−1 (at 50 A g−1). The amount of ash in the AC samples dramatically reduces the supercapacitor performances and significantly increases the resistances.

AB - This study proposes that high value-added activated carbon (AC) is produced from lignite (low rank coal) and used as electrode material in supercapacitors. In addition, the effects of the ash content of the activated carbon on supercapacitor performance are determined. The ACs at a temperature of 800 °C are produced in three different impregnation ratios (IR) (IR: 1, 2 and 4: KOH/precursor) using KOH as the activation agent. While the surface area of ​​the AC produced at IR4 is 2531.4 m2 g−1, it is determined as 1321.3 (IR1) and 1989.0 (IR2) m2 g−1 for the others. The pore size analysis of the samples shows that the mesopores are dominant in the IR1 (52.73%) and IR4 (88.74%) samples, while it is observed that the micropores are dominant in the IR2 (69.03%) sample. The IR4 sample gives excellent results. The cell specific capacitances of this sample are determined as 260.47 F g−1 (at 1 A g−1) and 150.3 F g−1 (at 50 A g−1). The amount of ash in the AC samples dramatically reduces the supercapacitor performances and significantly increases the resistances.

KW - Activated carbon

KW - Chemical activation

KW - Demineralisation

KW - Lignite

KW - Supercapacitor

UR - http://www.scopus.com/inward/record.url?scp=85121590600&partnerID=8YFLogxK

U2 - 10.1016/j.est.2021.103817

DO - 10.1016/j.est.2021.103817

M3 - Journal article

AN - SCOPUS:85121590600

SN - 2352-152X

VL - 46

JO - Journal of Energy Storage

JF - Journal of Energy Storage

M1 - 103817

ER -