Mesoporous Carbons Templated by PEO-PCL Block Copolymers as Electrode Materials for Supercapacitors

Jheng-Guang Li; Ya-Fan Ho; Mahmoud M M Ahmed; Heng-Chia Liang; Shiao-Wei Kuo

doi:10.1002/chem.201901724

Mesoporous Carbons Templated by PEO-PCL Block Copolymers as Electrode Materials for Supercapacitors

Chemistry. 2019 Aug 6;25(44):10456-10463. doi: 10.1002/chem.201901724. Epub 2019 Jul 8.

Authors

Jheng-Guang Li^{1

2}, Ya-Fan Ho¹, Mahmoud M M Ahmed¹, Heng-Chia Liang², Shiao-Wei Kuo^{1

3}

Affiliations

¹ Department of Materials and Optoelectronic Science, Center of Crystal Research, National Sun Yat-Sen University, Kaohsiung, Taiwan.
² R&D Department, Asia Carbons &, Technology Inc., Taoyuan, Taiwan.
³ Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 807, Taiwan.

PMID: 31206853
DOI: 10.1002/chem.201901724

Abstract

In this study, samples of activated mesoporous carbon are fabricated with pore structures with cylinder and gyroid nanostructures through the templating effect of amphiphilic poly(ethylene oxide-block-caprolactone) (PEO-PCL) and by using specific resol/PEO-PCL weight ratios (e.g., 60:40 for cylinders; 55:45 for gyroids). After carbonization and KOH activation, the activated mesoporous carbons were tested as electrode materials for electric double-layer capacitor (EDLC) supercapacitors. The electrochemical properties were examined by using three-electrode (6 m KOH_(aq) as electrolyte) and CR2032 coin-cell (1 m tetraethylammonium tetrafluoroborate (TEABF₄ )/CN as the electrolyte) systems. The gyroid carbon samples provided specific capacitances higher than those of the cylinder carbon samples in both aqueous and organic systems: 155 F g^-1 compared with 135 F g^-1 in 6 m KOH_(aq) , and 105.6 compared with 96 F g^-1 in 1 m TEABF₄ /MeCN, after 100 charge/discharge cycles. It is suspected that the bi-continuous mesochannels of the gyroid-type activated mesoporous carbons provided a relatively higher effective adsorption surface area; in other words, the greater surface area for energy storage originated from a moderate pore size and an interconnected pore structure.

Keywords: bi-continuous gyroid structures; block copolymers; mesoporous carbon; supercapacitors.