Understanding and Optimizing Capacitance Performance in Reduced Graphene‐Oxide Based Supercapacitors

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.

Flexible Fluorinated Graphene/Poly(vinyl Alcohol) Films toward High Thermal Management Capability

“…The XRD patterns are shown in Figure d. All rGO and FG- T samples exhibited an amorphous hump at about 24°, which was due to the fact that low-temperature calcination partially removed the oxygen-containing functional groups and reduced a small amount of the CC bonds. , In addition, the F atoms only partially replaced the oxygen-containing functional groups and could not completely cover the entire GO base surface. Therefore, surface defects cause a low crystallinity in FG- T samples.…”

Rational Design of Nanosheet Array-Like Layered-Double-Hydroxide-Derived NiCo2O4 In Situ Grown on Reduced-Graphene-Oxide-Coated Nickel Foam for High-Performance Solid-State Supercapacitors

“…Reduced graphene oxide (rGO) with excellent mechanical flexibility and stability, high electrical conductivity, high surface area, and light weight − has been regarded as an attractive substrate to fabricate multicomponent hybrid nanostructures with high capacity and good stability. The introduction of a rGO layer can improve the surface charge accumulation and electron collection efficiency of NiCo 2 O 4 species, as explained in a density functional theory (DFT) study, which is beneficial for enhancement of the redox activity of NiCo 2 O 4 .…”

Nitrogen-doped hierarchical porous carbons derived from biomass for oxygen reduction reaction

“…Carbon nanomaterials (Yan et al, 2023) have attracted worldwide attention since they have demonstrated great potential in energy storage (Fu et al, 2023;Gadipelli et al, 2023;Gao et al, 2023;Mo et al, 2023;Senokos et al, 2023) and conversion (Zhang et al, 2022;Kim et al, 2023;Lv et al, 2023;Peng et al, 2023) to relieve the environmental problem and energy crisis (Gao et al, 2022;Marangon et al, 2023;Yan et al, 2023). Carbon nanomaterials also play a significant role in the field of electrocatalysis of ORR due to their low cost, high performance and excellent stability (Zaman et al, 2022a).…”