Low-cost supercapacitor based on multi-walled carbon nanotubes and activated carbon derived from Moringa Oleifera fruit shells

Abstract

An electric double-layer capacitor (EDLC) was fabricated using multi-walled carbon nanotubes (MWCNT) and activated carbon (AC) derived from Moringa Oleifera fruit shells as electrode material. The carbonization temperature and the weight ratio of the fruit shells to the activating agent were varied to determine the best condition in the fabrication of the electrodes. Activation of the carbonized fruit shells by ZnCl 2 resulted in the formation of pores as verified by the scanning electron micrographs. Energy dispersive X-ray analyses show that the washing of the carbonized sample resulted in the removal of zinc and chlorine residues. The supercapacitor electrodes were fabricated by adding polyvinylidene fluoride and N-methylpyrrolidone to the MWCNT-AC mixture to form a slurry and was cast onto a nickel foam. The capacitance of the fabricated electrodes was determined using a potentiostat. The activated carbon with a carbonization temperature of 800 C and a 1:2 weight ratio between the fruit shells and ZnCl 2 was observed to have the highest capacitance of 130 F g À1 and was duplicated to fabricate the supercapacitor electrodes. A glass microfiber filter was soaked in 3 M KOH and placed in between the two electrodes. The specific capacitance of the EDLC was found to be 122 F g À1 at a current density of 0.5 A g À1 , average energy density of 17 W h kg À1 , average power density of 1.5 kW kg À1 and an equivalent series resistance of 1.6 Ω. After 100 scans with a scan rate of 0.1 V s À1 , the percent decrease in capacitance was calculated to be 2.65 % of its original capacitance.

Ultrahigh Capacitive Supercapacitor Derived from Self‐Oxygen Doped Biomass‐Based 3D Porous Carbon Sources

“…Previous investigations have also recorded several biomass species as precursors to porous carbon materials, including tea waste, [8] grape marcs, [9] Juncus effuses, [10] and jengkol shell [11] . Moringa Olifiera ‐based activated carbon produced a high surface area of 2,250 m 2 g −1 and specific energy of 25.8 Wh kg −1 , approximately three times the earlier report [12] . Meanwhile, mangosteen exhibited almost similar electrochemical properties with a surface area up to 2,300 m 2 g −1 [13] .…”

Nanofiber-enrich activated carbon coin derived from tofu dregs as electrode materials for supercapacitor

“…Biomass can easily be converted to activated carbon through heat treatment in a certain gaseous environment (Ar/N2/CO2/H2O), chemical impregnation (KOH, NaOH, ZnCl2, H3PO4), or a combination of both [11,12]. The main constituent components include lignocellulose consisting of hemicellulose, cellulose, and lignin, which allow the production of activated carbon with tubular [13], rod-like [14], strobili-fiber [15], microsphere [16], nanotube [17], and nanosheet [18] morphologies. Meanwhile, chemical impregnation with high-temperature pyrolysis in a certain gas environment can optimize the fibrils and cellulose in the biowaste components to produce high-density nanofibers [19].…”

Synthesis free‐template highly micro‐mesoporous carbon nanosheet as electrode materials for boosting supercapacitor performances

“…They are usually characterized by high surface area, 6 abundantly confirmed sub‐ultra‐microporous, 7 3D connected pores, 8 and 200 nm particle sizes 9 indispensable for enhancing its high specific energy. These properties are found in several electrode materials such as graphene/graphene oxide, 10,11 conduction polymers, 12 carbon nanotubes, 13 template‐carbon‐derived, 14 and porous carbon, 15,16 synthesized by different techniques. Zang et al stated that polymer‐based carbon sources have the potential to produce a high specific surface area of 3270 m 2 g −1 with a 3D pore structure made from reduced graphene oxide/polyaniline (rGO/PANI) hybrid film.…”