scholarly journals Effect of porosity enhancing agents on the electrochemical performance of high-energy ultracapacitor electrodes derived from peanut shell waste

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
N. F. Sylla ◽  
N. M. Ndiaye ◽  
B. D. Ngom ◽  
D. Momodu ◽  
M. J. Madito ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Activated Carbons ◽  
High Energy ◽  
Specific Power ◽  
Koh Activation ◽  
Peanut Shell ◽  
Equivalent Series Resistance ◽  
Shell Waste

Abstract In this study, the synthesis of porous activated carbon nanostructures from peanut (Arachis hypogea) shell waste (PSW) was described using different porosity enhancing agents (PEA) at various mass concentrations via a two-step process. The textural properties obtained were depicted with relatively high specific surface area values of 1457 m2 g−1, 1625 m2 g−1 and 2547 m2 g−1 for KHCO3, K2CO3 and KOH respectively at a mass concentration of 1 to 4 which were complemented by the presence of a blend of micropores, mesopores and macropores. The structural analyses confirmed the successful transformation of the carbon-containing waste into an amorphous and disordered carbonaceous material. The electrochemical performance of the material electrodes was tested in a 2.5 M KNO3 aqueous electrolyte depicted its ability to operate reversibly in both negative and positive potential ranges of 0.90 V. The activated carbon obtained from the carbonized CPSW:PEA with a mass ratio of 1:4 yielded the best electrode performance for all featured PEAs. The porous carbons obtained using KOH activation displayed a higher specific capacitance and the lower equivalent series resistance as compared to others. The remarkable performance further corroborated the findings linked to the textural and structural properties of the material. The assembled device operated in a neutral electrolyte (2.5 M KNO3) at a cell potential of 1.80 V, yielded a ca. 224.3 F g−1 specific capacitance at a specific current of 1 A g−1 with a corresponding specific energy of 25.2 Wh kg−1 and 0.9 kW kg−1 of specific power. This device energy was retained at 17.7 Wh kg−1 when the specific current was quadrupled signifying an excellent supercapacitive retention with a corresponding specific power of 3.6 kW kg−1. These results suggested that peanut shell waste derived activated carbons are promising candidates for high-performance supercapacitors.

scholarly journals Enhanced Electrochemical Behavior of Peanut-Shell Activated Carbon/Molybdenum Oxide/Molybdenum Carbide Ternary Composites

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1056
Author(s):  
Ndeye F. Sylla ◽  
Samba Sarr ◽  
Ndeye M. Ndiaye ◽  
Bridget K. Mutuma ◽  
Astou Seck ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Electrochemical Performance ◽  
Molybdenum Oxide ◽  
Specific Energy ◽  
Porous Carbon ◽  
Molybdenum Carbide ◽  
Electrode Materials ◽  
Specific Power ◽  
Peanut Shell ◽  
Symmetric Supercapacitor

Biomass-waste activated carbon/molybdenum oxide/molybdenum carbide ternary composites are prepared using a facile in-situ pyrolysis process in argon ambient with varying mass ratios of ammonium molybdate tetrahydrate to porous peanut shell activated carbon (PAC). The formation of MoO2 and Mo2C nanostructures embedded in the porous carbon framework is confirmed by extensive structural characterization and elemental mapping analysis. The best composite when used as electrodes in a symmetric supercapacitor (PAC/MoO2/Mo2C-1//PAC/MoO2/Mo2C-1) exhibited a good cell capacitance of 115 F g−1 with an associated high specific energy of 51.8 W h kg−1, as well as a specific power of 0.9 kW kg−1 at a cell voltage of 1.8 V at 1 A g−1. Increasing the specific current to 20 A g−1 still showcased a device capable of delivering up to 30 W h kg−1 specific energy and 18 kW kg−1 of specific power. Additionally, with a great cycling stability, a 99.8% coulombic efficiency and capacitance retention of ~83% were recorded for over 25,000 galvanostatic charge-discharge cycles at 10 A g−1. The voltage holding test after a 160 h floating time resulted in increase of the specific capacitance from 74.7 to 90 F g−1 at 10 A g−1 for this storage device. The remarkable electrochemical performance is based on the synergistic effect of metal oxide/metal carbide (MoO2/Mo2C) with the interconnected porous carbon. The PAC/MoO2/Mo2C ternary composites highlight promising Mo-based electrode materials suitable for high-performance energy storage. Explicitly, this work also demonstrates a simple and sustainable approach to enhance the electrochemical performance of porous carbon materials.

The Effect of Vacuum Annealing and HDDR Processing on the Electrochemical Characteristics of Activated Carbon and Graphene Oxide for the Production of Supercapacitors Electrodes

2020 ◽  
Vol 1012 ◽  
pp. 125-130
Author(s):  
P.V.D. Cruz ◽  
Ivana Conte Cosentino ◽  
E. Galego ◽  
D.S. Yoshikawa ◽  
R.N. Faria
Keyword(s):  
Activated Carbon ◽  
Specific Capacitance ◽  
Activated Carbons ◽  
Electrochemical Characteristics ◽  
Equivalent Series Resistance ◽  
Carbon Structure ◽  
Morphological Evaluation ◽  
Current Densities ◽  
Double Layer Capacitors ◽  
Parallel Resistance

Electric double-layer capacitors prepared using activated carbons have been subjected to vacuum heat treatments at low and high temperatures (200, 400, 600, 800 and 1000°C). The electrodes have been tested at a potential of 1.1 V employing a KOH electrolyte (1.0and 6.0 mol.L-1). The effect of or HDDR upon the electrical properties has been investigated by cyclic voltammetry. It has been shown that the specific capacitance at 5 msV-1 increases from 50 Fg-1 to 130 Fg-1 after a heat treatment at 400°C for 1 hour under back pump vacuum. At 400°C the diminution in the specific capacitance with higher scanning rate (10 msV-1) was much less pronounced (from 130 Fg-1 to 100 Fg-1). Equivalent series resistance (ESR) and equivalent parallel resistance of supercapacitors electrodes have also been investigated. Internal resistances of the supercapacitors were calculated using the galvanostatic curves at current densities (100 mAg-1).A compositional and morphological evaluation of these electrodes showed no significant change on the activated carbon structure.

scholarly journals High energy flexible symmetric supercapacitor fabricated using N-doped activated carbon derived from palm flower

2021 ◽  
Author(s):  
Malaya Kumar Sahoo ◽  
Ranga Rao Gangavarapu
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
High Surface ◽  
High Surface Area ◽  
High Energy ◽  
Carbonization Temperature ◽  
Koh Activation ◽  
Nitrogen Doped ◽  
Symmetric Supercapacitor ◽  
Activating Agent

Nitrogen doped activated carbons of high surface area are synthesized using palm flower biomaterial by KOH activation followed by pyrolysis. The concentration of the activating agent KOH and carbonization temperature...

scholarly journals 1.8 V Aqueous Symmetric Carbon-Based Supercapacitors with Agarose-Bound Activated Carbons in an Acidic Electrolyte

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1731
Author(s):  
Chih-Chung Lai ◽  
Feng-Hao Hsu ◽  
Su-Yang Hsu ◽  
Ming-Jay Deng ◽  
Kueih-Tzu Lu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Sulfuric Acid ◽  
Energy Density ◽  
Activated Carbons ◽  
High Energy ◽  
Aqueous Electrolytes ◽  
Alternative Material ◽  
Aqueous Cells ◽  
Acidic Electrolyte ◽  
Cycling Behavior

The specific energy of an aqueous carbon supercapacitor is generally small, resulting mainly from a narrow potential window of aqueous electrolytes. Here, we introduced agarose, an ecologically compatible polymer, as a novel binder to fabricate an activated carbon supercapacitor, enabling a wider potential window attributed to a high overpotential of the hydrogen-evolution reaction (HER) of agarose-bound activated carbons in sulfuric acid. Assembled symmetric aqueous cells can be galvanostatically cycled up to 1.8 V, attaining an enhanced energy density of 13.5 W h/kg (9.5 µW h/cm2) at 450 W/kg (315 µW/cm2). Furthermore, a great cycling behavior was obtained, with a 94.2% retention of capacitance after 10,000 cycles at 2 A/g. This work might guide the design of an alternative material for high-energy aqueous supercapacitors.

scholarly journals Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review

2012 ◽  
Vol 1 (3) ◽  
pp. 75 ◽  
Author(s):  
W.D.P Rengga ◽  
M. Sudibandriyo ◽  
M Nasikin
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Chemical Activation ◽  
High Energy ◽  
Hydrogen Gas ◽  
Agricultural Product ◽  
Adsorption Method ◽  
Modified Activated Carbon ◽  
Nano Size ◽  
Formaldehyde Adsorption

Gas storage is a technology developed with an adsorptive storage method, in which gases are stored as adsorbed components on the certain adsorbent. Formaldehyde is one of the major indoor gaseous pollutants. Depending on its concentration, formaldehyde may cause minor disorder symptoms to a serious injury. Some of the successful applications of technology for the removal of formaldehyde have been reported. However, this paper presents an overview of several studies on the elimination of formaldehyde that has been done by adsorption method because of its simplicity. The adsorption method does not require high energy and the adsorbent used can be obtained from inexpensive materials. Most researchers used activated carbon as an adsorbent for removal of formaldehyde because of its high adsorption capacity. Activated carbons can be produced from many materials such as coals, woods, or agricultural waste. Some of them were prepared by specific activation methods to improve the surface area. Some researchers also used modified activated carbon by adding specific additive to improve its performance in attracting formaldehyde molecules. Proposed modification methods on activation and additive impregnated carbon are thus discussed in this paper for future development and improvement of formaldehyde adsorption on activated carbon. Specifically, a waste agricultural product is chosen for activated carbon raw material because it is renewable and gives an added value to the materials. The study indicates that the performance of the adsorption of formaldehyde might be improved by using modified activated carbon. Bamboo seems to be the most appropriate raw materials to produce activated carbon combined with applying chemical activation method and addition of metal oxidative catalysts such as Cu or Ag in nano size particles. Bamboo activated carbon can be developed in addition to the capture of formaldehyde as well as the storage of adsorptive hydrogen gas that supports renewable energy. Keywords: adsorption; bamboo; formaldehyde; modified activated carbon; nano size particles

scholarly journals Fabrication of Hierarchical NiMoO4/NiMoO4 Nanoflowers on Highly Conductive Flexible Nickel Foam Substrate as a Capacitive Electrode Material for Supercapacitors with Enhanced Electrochemical Performance

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1143 ◽  
Author(s):  
Anil Yedluri ◽  
Tarugu Anitha ◽  
Hee-Je Kim
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Electrode Material ◽  
High Performance ◽  
Nickel Foam ◽  
High Specific Capacitance ◽  
High Energy ◽  
High Energy Density ◽  
Charge Discharge

Hierarchical NiMoO4/NiMoO4 nanoflowers were fabricated on highly conductive flexible nickel foam (NF) substrates using a facile hydrothermal method to achieve rapid charge-discharge ability, high energy density, long cycling lifespan, and higher flexibility for high-performance supercapacitor electrode materials. The synthesized composite electrode material, NF/NiMoO4/NiMoO4 with a nanoball-like NF/NiMoO4 structure on a NiMoO4 surface over a NF substrate, formed a three-dimensional interconnected porous network for high-performance electrodes. The novel NF/NiMoO4/NiMoO4 nanoflowers not only enhanced the large surface area and increased the electrochemical activity, but also provided an enhanced rapid ion diffusion path and reduced the charge transfer resistance of the entire electrode effectively. The NF/NiMoO4/NiMoO4 composite exhibited significantly improved supercapacitor performance in terms of a sustained cycling life, high specific capacitance, rapid charge-discharge capability, high energy density, and good rate capability. Electrochemical analysis of the NF/NiMoO4/NiMoO4 nanoflowers fabricated on the NF substrate revealed ultra-high electrochemical performance with a high specific capacitance of 2121 F g−1 at 12 mA g−1 in a 3 M KOH electrolyte and 98.7% capacitance retention after 3000 cycles at 14 mA g−1. This performance was superior to the NF/NiMoO4 nanoball electrode (1672 F g−1 at 12 mA g−1 and capacitance retention 93.4% cycles). Most importantly, the SC (NF/NiMoO4/NiMoO4) device displayed a maximum energy density of 47.13 W h kg−1, which was significantly higher than that of NF/NiMoO4 (37.1 W h kg−1). Overall, the NF/NiMoO4/NiMoO4 composite is a suitable material for supercapacitor applications.

Preparation of Activated Carbon Derived from Water Hyacinth as Electrode Active Material for Li-Ion Supercapacitor

2020 ◽  
Vol 1000 ◽  
pp. 50-57
Author(s):  
Jagad Paduraksa ◽  
Muhammad Luthfi ◽  
Ariono Verdianto ◽  
Achmad Subhan ◽  
Wahyu Bambang Widayatno ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Water Hyacinth ◽  
Electrode Materials ◽  
Storage System ◽  
Active Material ◽  
Lithium Ion ◽  
High Energy ◽  
Specific Power ◽  
Full Cell ◽  
Lithium Ion Capacitor

Lithium-Ion Capacitor (LIC) has shown promising performance to meet the needs of high energy and power-density-energy storage system in the era of electric vehicles nowadays. The development of electrode materials and electrolytes in recent years has improvised LIC performance significantly. One of the active materials of LIC electrodes, activated carbon (AC), can be synthesized from various biomass, one of which is the water hyacinth. Its abundant availability and low utilization make the water hyacinth as a promising activated carbon source. To observe the most optimal physical properties of AC, this study also compares various activation temperatures. In this study, full cell LIC was fabricated using LTO based anode, and water hyacinth derived AC as the cathode. The LIC full cell was further characterized to see the material properties and electrochemical performance. Water hyacinth derived LIC can achieve a specific capacitance of 32.11 F/g, the specific energy of 17.83 Wh/kg, and a specific power of 160.53 W/kg.

scholarly journals Glycerolized Li+ Ion Conducting Chitosan-Based Polymer Electrolyte for Energy Storage EDLC Device Applications with Relatively High Energy Density

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1433 ◽  
Author(s):  
Ahmed S. F. M. Asnawi ◽  
Shujahadeen B. Aziz ◽  
Muaffaq M. Nofal ◽  
Muhamad H. Hamsan ◽  
Mohamad A. Brza ◽  
...  
Keyword(s):  
Energy Density ◽  
Polymer Electrolyte ◽  
Specific Capacitance ◽  
Power Density ◽  
High Specific Capacitance ◽  
High Energy ◽  
High Energy Density ◽  
Equivalent Series Resistance ◽  
Ion Conducting ◽  
High Dielectric

In this study, the solution casting method was employed to prepare plasticized polymer electrolytes of chitosan (CS):LiCO2CH3:Glycerol with electrochemical stability (1.8 V). The electrolyte studied in this current work could be established as new materials in the fabrication of EDLC with high specific capacitance and energy density. The system with high dielectric constant was also associated with high DC conductivity (5.19 × 10−4 S/cm). The increase of the amorphous phase upon the addition of glycerol was observed from XRD results. The main charge carrier in the polymer electrolyte was ion as tel (0.044) < tion (0.956). Cyclic voltammetry presented an almost rectangular plot with the absence of a Faradaic peak. Specific capacitance was found to be dependent on the scan rate used. The efficiency of the EDLC was observed to remain constant at 98.8% to 99.5% up to 700 cycles, portraying an excellent cyclability. High values of specific capacitance, energy density, and power density were achieved, such as 132.8 F/g, 18.4 Wh/kg, and 2591 W/kg, respectively. The low equivalent series resistance (ESR) indicated that the EDLC possessed good electrolyte/electrode contact. It was discovered that the power density of the EDLC was affected by ESR.

scholarly journals Accelerating the Oxygen Reduction Reaction and Oxygen Evolution Reaction Activities of N and P Co-Doped Porous Activated Carbon for Li-O2 Batteries

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1316
Author(s):  
Hyun-Gi Jo ◽  
Hyo-Jin Ahn
Keyword(s):  
Activated Carbon ◽  
High Energy ◽  
Reduction Reaction ◽  
Discharge Voltage ◽  
Koh Activation ◽  
Energy Storage Devices ◽  
Metal Free ◽  
Large Active Area ◽  
Co Doped ◽  
Porous Activated Carbon

Rechargeable lithium–oxygen (Li-O2) batteries represent state-of-the-art electrochemical energy storage devices that provide high energy densities. However, their commercialization is challenging owing to their low charging/discharging efficiencies, short battery lives, high overpotentials, and high cathode manufacturing costs. In this study, we prepared a metal-free, N,P co-doped, porous activated carbon (N,P-PAC) electrode via KOH activation and P doping for application as a Li-O2 battery cathode. When used in a rechargeable Li-O2 battery, the N,P-PAC cathode showed a high specific discharge capacity (3724 mA h g−1 at 100 mA g−1), an excellent cycling stability (25 cycles with a limit capacity of 1000 mA h g−1), and a low charge/discharge voltage gap (1.22 V at 1000 mA h g−1). The N,P-PAC electrode showed a low overpotential (EOER-ORR) of 1.54 V. The excellent electrochemical performance of the N,P-PAC electrode can mainly be attributed to its large active area and oxygen-containing functional groups generated via KOH activation and P-doping processes. Therefore, the N,P-PAC prepared in this study was found to be a promising eco-friendly and sustainable metal-free cathode material for Li-O2 batteries.

Effect of Activation Agents on COD Reduction Using Activated Carbon from Agricultural Residue

2020 ◽  
Vol 1010 ◽  
pp. 453-458
Author(s):  
Mohd Zazmiezi Mohd Alias ◽  
Rozidaini Mohd Ghazi ◽  
Nik Raihan Nik Yusoff ◽  
Mohd Hafiz Jamaludin
Keyword(s):  
Activated Carbon ◽  
Phosphoric Acid ◽  
Potassium Hydroxide ◽  
Activated Carbons ◽  
Oxygen Demand ◽  
Koh Activation ◽  
Ftir Analysis ◽  
Agricultural Residue ◽  
Cod Reduction ◽  
Activating Agent

This study investigated the effect of activating agent on activated carbon preparation and potential chemical oxygen demand (COD) reduction using activated carbons (AC) prepared. Zinc chloride, phosphoric acid and potassium hydroxide were utilized in impregnation of bamboo and rice husk. Result of SEM-EDX, FTIR as well as COD reduction were compared and discussed. The SEM displayed highest porosity in AC using KOH activation. FTIR analysis displayed obvious difference for each activation. AC using KOH activation obtained highest COD reduction.

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