A1 Journal article (refereed), original research

Conversion of cellulose to activated carbons for high-performance supercapacitors


Open Access publication

Publication Details
Authors: Sermyagina Ekaterina, Murashko Kirill, Nevstrueva Daria, Pihlajamäki Arto, Vakkilainen Esa
Publisher: Estonian Agricultural University
Publication year: 2020
Language: English
Related Journal or Series Information: Agronomy Research
Volume number: 18
ISSN: 1406-894X
JUFO-Level of this publication: 1
Open Access: Open Access publication

Abstract

Biomass-derived activated carbons are promising materials that can be used in various
applications. Current work investigates the possibilities of the cellulose-derived activated carbons
in substituting the commercial alternatives for the supercapacitors’ electrodes with high
efficiency, stable performance and relatively low cost. Hydrothermal carbonization (HTC)
followed by chemical activation with KOH is used to convert cellulose into highly porous
activated carbons. The effect of HTC parameters on the material porosity development and
electrochemical properties of the electrodes is evaluated with several variations of the residence
time and the weight ratio between cellulose and water during the pretreatment. The analysis
shows that intensification of the HTC process (longer residence time and higher water/cellulose
ratio) results in increase of the surface area of both hydrochar samples and subsequent activated
carbons: with the highest surface area for the sample produced after 2 h HTC treatment with
water/cellulose ratio of 6/1 – 2,645 m2 g
-1
. As for the electrochemical analysis, the highest values
of the specific capacitance are found for the samples produced from 2 h HTC treatment:
110.3 F g
-1
(water/cellulose ratio of 3/1) and 102.5 F g
-1
(water/cellulose ratio of 6/1).
Additionally, it is noted that electrodes produced from the samples treated during 4 h have higher
impedance at low operation frequency. The present study proves the possibility to substitute
commercial activated carbons with cellulose-derived materials, the porosity of which can be
tuned accordingly already during the pretreatment step.


Last updated on 2020-22-06 at 09:55