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Understanding and Optimizing Capacitance Performance in Reduced Graphene-Oxide Based Supercapacitors.

Published version
Peer-reviewed

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Authors

Gadipelli, Srinivas  ORCID logo  https://orcid.org/0000-0002-1362-6905
Guo, Jian 
Li, Zhuangnan 
Howard, Christopher A 
Liang, Yini 

Abstract

Reduced graphene-oxide (RGO)-based electrodes in supercapacitors deliver high energy/power capacities compared to typical nanoporous carbon materials. However, extensive critical analysis of literature reveals enormous discrepancies (up to 250 F g-1 ) in the reported capacitance (variation of 100-350 F g-1 ) of RGO materials synthesized under seemingly similar methods, inhibiting an understanding of capacitance variation. Here, the key factors that control the capacitance performance of RGO electrodes are demonstrated by analyzing and optimizing various types of commonly applied electrode fabrication methods. Beyond usual data acquisition parameters and oxidation/reduction properties of RGO, a substantial difference of more than 100% in capacitance values (with change from 190 ± 20 to 340 ± 10 F g-1 ) is found depending on the electrode preparation method. For this demonstration, ≈40 RGO-based electrodes are fabricated from numerous distinctly different RGO materials via typically applied methods of solution (aqueous and organic) casting and compressed powders. The influence of data acquisition conditions and capacitance estimation practices are also discussed. Furthermore, by optimizing electrode processing method, a direct surface area governed capacitance relationship for RGO structures is revealed.

Description

Keywords

electrode fabrication methods, graphene materials, structure-performance relationships, supercapacitors

Journal Title

Small Methods

Conference Name

Journal ISSN

2366-9608
2366-9608

Volume Title

Publisher

Wiley
Sponsorship
EPSRC (EP/R511638/1, EP/K021192/1, EP/S018204/2, EP/R023581/1, EP/W03395X/1, EP/W033321/1)
Science Specialty Program of Sichuan University (2020SCUNL210)
Shearing (CiET1718∖59)
Brett (RCSRF2021/13/53)
Fundamental Research Funds for the Central Universities (2021SCU12116)