Graphene Synthesis by Ultrasound Energy Assisted Exfoliation of Graphite in Various Solvents

Gürünlü, Betül; Taşdelen-Yücedağ, Çiğdem

doi:10.3762/bxiv.2020.114.v1

Cited by 4 publications

(3 citation statements)

References 43 publications

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“…The peaks at 2θ ¼ 26.5 , 38.2 , 43.1 , 54.6 , 64.3 , and 77.4 are ascribed to (002), (100), (101), (004), (103), and (110) crystal planes in the structure of graphite, respectively. [39] The SEM images of AC and graphene/AC composites with different percentages of graphene coated on the aluminum substrate by doctor blade process are shown in Figure 2. SEM images in Figure 2a,c,e,g demonstrate the uniform coverage of the coated electrode materials on the current collectors.…”

Section: Resultsmentioning

confidence: 99%

Improving the Electrochemical Performance of Pouch Cell Electric Double‐Layer Capacitors by Integrating Graphene Nanoplates into Activated Carbon

et al. 2021

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Herein, activated carbon (AC) is composited with multiple weight ratios of graphene nanoplates through a facile and scalable technique, including sonicating and vacuum mixing in a slurry to fabricate pouch cell electric double-layer capacitors (EDLCs). Among the fabricated devices, the EDLC made of 2 wt% graphene/AC composite demonstrated the best electrochemical performance by enhancing the specific capacitance of AC EDLC from 27.3 to 39.3 F g À1 at 0.05 A g À1 current density. Moreover, the addition of graphene to AC leads to a more ideal capacitive behavior, reduction of charge transfer resistance (R ct ) of the AC EDLC from 2.04 Ω to below 0.05 Ω, and the decrease of the ohmic drop at a current density of 2 A g À1 from 18.7% to 5.7%. 2 wt% graphene was considered as the optimum amount to be added to AC to increase the specific capacitance on average by 40% and improve the capacitance retention to 97% after 1000 cycles at 1 A g À1 . Furthermore, the fabricated EDLC based on the optimum ratio of graphene to AC possessed satisfactory energy densities of 13.7 and 8.3 Wh kg À1 at 50 and 2000 W kg À1 power densities, respectively.

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Section: Resultsmentioning

confidence: 99%

Improving the Electrochemical Performance of Pouch Cell Electric Double‐Layer Capacitors by Integrating Graphene Nanoplates into Activated Carbon

et al. 2021

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“…Due to its high exfoliation efficiency, sono‐exfoliation is regarded as an important method for producing graphene via exfoliating graphite in liquid medium. The steps involved in the sono‐exfoliation process are as follows: (1) dispersion of graphite in a solvent, (2) exfoliation using probe sonication, and (3) purification 31 . The use of an external driving force, such as ultrasonic waves, overcomes the Van der Waals interactions between the graphite layers, allowing the solvent molecules to intercalate 32 .…”

Section: Introductionmentioning

confidence: 99%

“…The steps involved in the sono-exfoliation process are as follows: (1) dispersion of graphite in a solvent, (2) exfoliation using probe sonication, and (3) purification. 31 The use of an external driving force, such as ultrasonic waves, overcomes the Van der Waals interactions between the graphite layers, allowing the solvent molecules to intercalate. 32 Even though, sono-exfoliation is widely employed for producing high quality single or few layered graphene from bulk graphite, this method has been rarely explored for biomass activated carbon.…”

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confidence: 99%

Sono‐exfoliated graphene‐like activated carbon from hazelnut shells for flexible supercapacitors

Reddygunta

Callander

Šiller

et al. 2022

Intl J of Energy Research

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Currently, more than 80% of commercial supercapacitors utilize chemically synthesized carbon nanomaterials which are expensive and necessitates non-renewable resources. Employing renewable, environment friendly and naturally available biomass feedstock as precursor for producing carbon materials is a low-cost and sustainable way for designing the electrodes of supercapacitors. In the present study, high surface area hierarchical porous multilayered graphene-like carbon is obtained via room temperature sono-exfoliation of the activated carbon synthesized via simple and environmentally friendly hydrothermal carbonization and potassium bicarbonate activation of waste hazelnut shells as the precursor. The high surface area graphene-like carbon showed excellent electrochemical performance with specific capacitance of 320.9 F g À1 at 0.2 A g À1 current density and exceptional capacitance retention of 77.8% at 2 A g À1 current density after 10 000 cycles in 1 M Na 2 SO 4 electrolyte. Moreover, flexible supercapacitors fabricated using sonoexfoliated graphene-like activated carbon coated stainless steel mesh electrodes and biopolymer gel electrolyte exhibits an outstanding energy density of 38.7 W h kg À1 and power density of 198.4 W kg À1 . These results show that mechanically exfoliated graphene-like activated carbon derived from hazelnut shells exhibit superior electrochemical performance that can compete with other activated carbon materials used in energy storage devices for real time applications.

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Natural Solid-State Hydrogel Electrolytes Based on 3D Pure Cotton/Graphene for Supercapacitor Application

et al. 2023

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A conductive cotton hydrogel with graphene and ions can come into contact with electrodes in solid electrolytes at the molecular level, leading to a more efficient electrochemical process in supercapacitors. The inherently soft nature of cotton mixed with hydrogel provides superior flexibility of the electrolyte, which benefits the devices in gaining high flexibility. Herein, we report on the current progress in solid-state hydrogel electrolytes based on 3D pure cotton/graphene and present an overview of the future direction of research. The ionic conductivity of a complex hydrogel significantly increased by up to 13.9 × 10−3 S/cm at 25 °C, due to the presence of graphene, which increases ionic conductivity by providing a smooth pathway for the transport of charge carriers and the polymer. Furthermore, the highest specific capacitance of 327 F/g at 3 mV/s was achieved with cyclic voltammetry measurement and a galvanostatic charge–discharge measurement showed a peak value of 385.4 F/g at 100 mA/g current density. Furthermore, an electrochemical analysis demonstrated that a composite cotton/graphene-based hydrogel electrolyte is electrically stable and could be used for the design of next-generation supercapacitors.

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Graphene Synthesis by Ultrasound Energy Assisted Exfoliation of Graphite in Various Solvents

Cited by 4 publications

References 43 publications

Improving the Electrochemical Performance of Pouch Cell Electric Double‐Layer Capacitors by Integrating Graphene Nanoplates into Activated Carbon

Improving the Electrochemical Performance of Pouch Cell Electric Double‐Layer Capacitors by Integrating Graphene Nanoplates into Activated Carbon

Sono‐exfoliated graphene‐like activated carbon from hazelnut shells for flexible supercapacitors

Natural Solid-State Hydrogel Electrolytes Based on 3D Pure Cotton/Graphene for Supercapacitor Application

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