Preparation of highly expanded graphene with large surface area and its additional conductive effect for EDLC performance

Abstract

Expanded graphene (EG) has been produced using fast oxidation/intercalation process. The as prepared EG were then used as conductive additive to study the electrochemical properties of activated carbon based electric double layered supercapacitors (EDLCs). The physiochemical properties of EG were studied using scanning electron microscopy, Raman spectroscopic techniques, atomic force microscopy and energy dispersive X-ray analysis. The electrochemical properties were studied using charge/discharge cyclic voltammetry and electrochemical impedance spectroscopy. All the electrochemical tests were carried out in 1 M, TEA BF 4 in acetonitrile as a suitable electrolyte for our AC based supercapacitors. Electrochemical test reveals that EG greatly affect the conductivity of the ions through the AC/EG interface. The specific capacitance remains the same for smaller values of EG in the composites electrodes. These results also evident the optimum loading of graphene in the future graphene based EDLCs.

One‐stepsynthesis of nitrogen‐doped graphene powders and application of them ashigh‐performancesymmetrical coin cell supercapacitors in different aqueous electrolyte

“…Surface area is one of the important factors affecting the specific capacitance especially in EDLC supercapacitors. 61,62 The grinding process with the ultrasonic homogenizer was used to increase the surface area of the N3-GP graphene powder in this work, from which we obtained the highest specific capacitance value. For this purpose, when the grinding process was done for 4 hours, the particle size was minimum.…”

Review—Recent Advancements in Graphene-Based Electrodes for Lithium-Ion Batteries

“…The production process has a significant impact on graphene's lithium storage capacity, as demonstrated. 47,48 Graphene's unique properties have made it a frontrunner as a potential replacement for traditional anode materials in recent years. Theoretical capacities of roughly 744 mAh g −1 for Li 2 C 6 formation and 1116 mAh g −1 for Li 3 C 6 creation are quite high, 49 with exceptional mechanical strength of about 2630 m 2 /g, 50 excellent heat conduction reaching up to 5000 W/mk, 51 surface area of 630 m 2 /g, and extraordinary charge carriers can move about 200,000 cm 2 /vs at room temperature.…”

“…However, getting silicon particles to spread out evenly over graphene sheets has proved to be a difficult challenge. 48 The abundance of silicon dioxide on Earth makes it a preferable anode material compared to other silicon oxides. 61,62 Recent studies have concentrated on improving nanoparticles of silicon and their electrochemical characteristics for LIBs as anode materials by synthesizing silicon-doped graphene composites through several methods.…”

Boron Carbide as an Electrode Material: Tailoring Particle Morphology to Control Capacitive Behaviour

“…Thus, good electrically conductive materials with a high surface area are desired to achieve high capacitance values of EDLCs. In this respect, carbon-based materials with varying morphologies, such as nanosheets, nanotubes, and fibers, have been comprehensively investigated for EDLCs [ 13 , 14 , 15 , 16 , 17 ]. On the other hand, capacitance generation in pseudocapacitors are based on reversible Faradaic processes [ 18 ].…”