Porous activated carbon monolith with nanosheet/nanofiber structure derived from the green stem of cassava for supercapacitor application

Abstract

Carbonization and activation have been exploited as an economic and efficient approach toward the production of porous activated carbon monolith derived from green stem of cassava (GSC). In addition, ZnCl 2 was used as a chemical activator agent at various concentrations, therefore serving as a key factor in the development of porous carbon. The carbonization process (N 2) was integrated with physical activation (CO 2), and then N 2 sorption, scanning electron microscopy, X-ray diffraction, energy dispersive X-ray were examined to evaluate the specific surface area, pore structure characteristic, morphology structure, crystallinity, and the surface element, respectively. Furthermore, cyclic voltammetry was used to measure the electrochemical performance, through a two-electrode system in 1M H 2 SO 4. Therefore, the synthesized porous activated carbon exhibits a micropores-mesopores combination, and the optimized sample demonstrated nanosheet and nanofiber structures. The results show a high electrochemical behavior in 1M H 2 SO 4 electrolytes, by the electrodes, with specific capacitance, energy, and power densities of 164.58 F g −1 , 22.86 Wh kg −1 , and 82.38 W kg −1 , respectively. This route confirms the opportunity of using novel GSC in the production of porous carbon monolith with nanosheet/nanofiber structure for supercapacitor applications. K E Y W O R D S activated carbon, carbon porous, green stem of cassava, monolith, supercapacitor 1 | INTRODUCTION Green, renewable, and sustainable sources of energy systems are obtainable through the conversion of wind, water, and solar energy, 1 hence proper capture and storage is required for environmental friendly and economic application. 2 Meanwhile, supercapacitors possessing high power density, high charge-discharge rate, long cycle life, have the ability to store energy in the form of electric charges, 3 by providing a performance between capacitors and batteries. Conversely, the difference between both is that capacitors store and deliver energy incredibly quickly, while batteries have an ability to store high energy densities and also high voltages. 4 However, the main challenge of supercapacitor is related to the energy density entry through the narrow gap of batteries. Several electrode materials have been developed and suggested to improve energy density, power density, and cycle life of supercapacitor, 5 and three types were identified. These were then classified into carbonaceous

Biomass‐based Self‐single‐oxygen Heteroatom‐doped Hierarchical Porous Carbon Nanosheets for High‐performance Symmetrical Supercapacitors

“…[20][21][22] Until presently, these excellent properties are possessed from several biomass wastes. Among of them successfully displayed 2D nanofiber and nanosheet carbon nanostructures such as bacterial cellulose, [23] tofu dregs, [24] pineapple and cassava leaves, [25,26] Moringa oleifera stem, [27] and Prosopis juliflora wood. [6] Meanwhile, the 3D hierarchical porous carbon is being generated from watermelon, [28] jujube fruits, [29] garlic seed, [30] corn husk, [31] and mangosteen peel.…”

Ball‐milling route to design hierarchical nanohybrid cobalt oxide structures with cellulose nanocrystals interface for supercapacitors

“…However, the use of carbon-based materials in combination to metal nanoarchitectures for energy storage applications shows reliable results due to its structural defects and synergistic heteroatom interference. 17,18 Cobalt metal and its oxide derivatives have garnered interest because of their wide range of industrial applications. Due to its promising semiconducting properties, it has been incorporated into other nanoparticles as a dopant.…”

“…Afresh report of Mallem et al 16 on designing potato chip textured zero‐dimensional spinel Zinc‐Cobalt oxide nanoparticle electrodes showed interesting electrochemical performance. However, the use of carbon‐based materials in combination to metal nanoarchitectures for energy storage applications shows reliable results due to its structural defects and synergistic heteroatom interference 17,18 …”

A dual‐activation strategy to tailor the hierarchical porous structure of biomass‐derived carbon for ultrahigh rate supercapacitor

“…electrode due to the adjustable pore sizes, large SSA, and excellent physicochemical stability. 4,[8][9][10] At present, plant-derived porous carbons are widely used in the supercapacitors electrode because of their low cost, simple preparation process, and abundant resource. 1,2,6,[10][11][12][13][14][15] However, plant-derived porous carbons still face the following challenges when used for the supercapacitor electrode materials: (a) the strong cross-linking among lignin, cellulose, and hemicellulose in plants makes it difficult to further adjust the morphology as well as pore distribution.…”

“…According to the energy storage mechanism of double‐layer supercapacitors, it is essential to develop electrode materials with highly effective specific surface area (SSA) for ion storage and hierarchical porous structure for ion diffusion, respectively 4 . Carbon materials such as carbon nanofibers, graphene, carbon nanotubes, carbon spheres, and porous carbon have been extensively researched for supercapacitors electrode due to the adjustable pore sizes, large SSA, and excellent physicochemical stability 4,8‐10 . At present, plant‐derived porous carbons are widely used in the supercapacitors electrode because of their low cost, simple preparation process, and abundant resource 1,2,6,10‐15 …”