Structural and Electrochemical Properties of Physically and Chemically Activated Carbon Nanoparticles for Supercapacitors

Abstract

The demand for supercapacitors has been high during the integration of renewable energy devices into the electrical grid. Although activated carbon materials have been widely utilized as supercapacitor electrodes, the need for economic and sustainable processes to extract and activate carbon nanomaterials is still crucial. In this work, the biomass waste of date palm fronds is converted to a hierarchical porous nanostructure of activated carbon using simple ball-milling and sonication methods. Chemical and physical activation agents of NaOH and CO2, receptively, were applied on two samples separately. Compared with the specific surface area of 603.5 m²/g for the CO2-activated carbon, the NaOH-activated carbon shows a higher specific surface area of 1011 m2/g with a finer nanostructure. Their structural and electrochemical properties are functionalized to enhance electrode–electrolyte contact, ion diffusion, charge accumulation, and redox reactions. Consequently, when used as electrodes in an H2SO4 electrolyte for supercapacitors, the NaOH-activated carbon exhibits an almost two-fold higher specific capacitance (125.9 vs. 56.8 F/g) than that of the CO2-activated carbon at the same current density of 1 A/g. Moreover, using carbon cloth as a current collector provides mechanical flexibility to our electrodes. Our practical approach produces cost-effective, eco-friendly, and flexible activated carbon electrodes with a hierarchical porous nanostructure for supercapacitor applications.

Preparation and Characterization of Physically Activated Carbon and Its Energetic Application for All-Solid-State Supercapacitors: A Case Study

“…A NaOH-activated carbon electrode prepared from date palm fronds showed a specific capacitance up to 156.8 F g –1 at 0.4 A g –1 . A similar value of 150 F g –1 at 0.3 A g –1 was reported by Farma et al using KOH-CO 2 -activated carbon from empty fruit bunches of oil palm .…”

“…A NaOH-activated carbon electrode prepared from date palm fronds showed a specific capacitance up to 156.8 F g −1 at 0.4 A g −1 . 76 A similar value of 150 F g −1 at 0.3 A g −1 was reported by Farma et al using KOH-CO 2 -activated carbon from empty fruit bunches of oil palm. 77 In another study, a commercial activated carbon was treated and added to waste palm and activated with KOH that exhibited 226.0 F g −1 at 0.5 A g −1 using a PVA-based gel electrolyte.…”

“…78 A CO 2 -activated carbon electrode derived from date palm fronds at the same current density of 1 A g −1 achieved 56.8 F g −1 . 76 The electrodes assembled from our prepared physically activated carbon showed a specific capacitance of 88.4 F g −1 at 0.5 A g −1 , demonstrating the significant contribution of this work to the research community. A detailed comparison of various activated carbons and their supercapacitors is shown in Table S1.…”

Ion Dynamics at the Carbon Electrode/Electrolyte Interface: Influence of Carbon Nanotubes Types

“…This result can be attributed to the difference of material form illustrated by the difference of specific surface, which is higher in the case of the DWCNTs, almost two times higher, compared with the value of the MWCNTs. A higher capacitance was also found, in comparison with values given by compact films, with different nanostructured materials as titanium dioxide based composite nanotube-arrays, MnO 2 electrodes, or activated carbon nanoparticles [ 48 , 49 , 50 ].…”

Single and Double Layer of Monoclinic VO2 Ink‐Based Printed and Interdigitated Supercapacitors

“…It has been highly required to fabricate interdigitated supercapacitors and batteries economically and eco-friendly to be connected with renewable energy sources such as photovoltaic cells or piezoelectric nanogenerators. The electrode materials for supercapacitors can be categorized into carbon-based materials, [1][2][3] conductive polymers, [4][5][6] MXenes, [7][8][9] metal and covalent organic frameworks, [10][11][12] and transition metal compounds. [13][14][15] In particular, vanadium-based materials such as vanadium oxides [16] and vanadium nitrides [17] have emerged as attractive electrode candidates due to the multiple valence states of the vanadium (V), its cost-effectivity, good conductivity, high theoretical capacitance, wide potential window, robust chargedischarge stability, and active redox reversibility.…”