scholarly journals Flax-Derived Carbon: A Highly Durable Electrode Material for Electrochemical Double-Layer Supercapacitors

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2229
Author(s):  
Petr Jakubec ◽  
Stanislav Bartusek ◽  
Josef Jan Dvořáček ◽  
Veronika Šedajová ◽  
Vojtěch Kupka ◽  
...  

Owing to their low cost, good performance, and high lifetime stability, activated carbons (ACs) with a large surface area rank among the most popular materials deployed in commercially available electrochemical double-layer (EDLC) capacitors. Here, we report a simple two-step synthetic procedure for the preparation of activated carbon from natural flax. Such ACs possess a very high specific surface area (1649 m2 g–1) accompanied by a microporous structure with the size of pores below 2 nm. These features are behind the extraordinary electrochemical performance of flax-derived ACs in terms of their high values of specific capacitance (500 F g–1 at a current density of 0.25 A g–1 in the three-electrode setup and 189 F g–1 at a current density of 0.5 A g–1 in two-electrode setup.), high-rate stability, and outstanding lifetime capability (85% retention after 150,000 charging/discharging cycles recorded at the high current density of 5 A g–1). These findings demonstrate that flax-based ACs have more than competitive potential compared to standard and commercially available activated carbons.

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2371 ◽  
Author(s):  
Ram Lal Shrestha ◽  
Timila Shrestha ◽  
Birendra Man Tamrakar ◽  
Rekha Goswami Shrestha ◽  
Subrata Maji ◽  
...  

Nanoporous activated carbons-derived from agro-waste have been useful as suitable and scalable low-cost electrode materials in supercapacitors applications because of their better surface area and porosity compared to the commercial activated carbons. In this paper, the production of nanoporous carbons by zinc chloride activation of Washnut seed at different temperatures (400–1000 °C) and their electrochemical supercapacitance performances in aqueous electrolyte (1 M H2SO4) are reported. The prepared nanoporous carbon materials exhibit hierarchical micro- and meso-pore architectures. The surface area and porosity increase with the carbonization temperature and achieved the highest values at 800 °C. The surface area was found in the range of 922–1309 m2 g−1. Similarly, pore volume was found in the range of 0.577–0.789 cm3 g−1. The optimal sample obtained at 800 °C showed excellent electrochemical energy storage supercapacitance performance. Specific capacitance of the electrode was calculated 225.1 F g−1 at a low current density of 1 A g−1. An observed 69.6% capacitance retention at 20 A g−1 indicates a high-rate capability of the electrode materials. The cycling stability test up to 10,000 cycles revealed the outstanding stability of 98%. The fascinating surface textural properties with outstanding electrochemical performance reveal that Washnut seed would be a feasible agro-waste precursor to prepare nanoporous carbon materials as a low-cost and scalable supercapacitor electrode.


RSC Advances ◽  
2018 ◽  
Vol 8 (52) ◽  
pp. 29767-29774 ◽  
Author(s):  
L. Zheng ◽  
W. B. Li ◽  
J. L. Chen

Nitrogen doped activated carbons with high surface area up to 3797 m2 g−1 exhibit specific capacitance of 231 F g−1 at a current density of 10 A g−1.


1995 ◽  
Vol 18 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Sui-Yang Huang ◽  
Ladislav Kavan ◽  
Andreas Kay ◽  
Michael Grätzel ◽  
Ivan Exnar

Nanocrystalline TiO2films were explored for the first time as electrode material for a rechargeable lithium intercalation cell, i.e., Li/LiCF3SO3+ PC/TiO2. Two kinds of nanocrystalline films, TiO2F387 (Degussa) and TiO2colloid-240, were investigated. These films exhibited excellent performance renderings them a promising choice for secondary battery applications. At a current density of 0.01 mA/cm2, two voltage plateaus at 1.78 and 1.89 V were observed for TiO2F387 films during charge and discharge, respectively. The TiO2electrode charge capacity per unit weight rose with decreasing current density. The highest capacity, obtained at a current density of 0.005 mA/cm2and a final discharge voltage of 1.4 V, was 265 mAh/g corresponding to a lithium insertion ratio ofx= 0.8. Nanocrystalline TiO2colloid-240 films showed a similar performance. The cycle life of a TiO2colloid-240 cell at a high current density was found to be excellent; a capacity loss lower than 14% has been observed over 100 charge/discharge cycles.


2013 ◽  
Vol 16 (1) ◽  
pp. 22-31
Author(s):  
Phung Thi Kim Le ◽  
Kien Anh Le

Agricultural wastes are considered to be a very important feedstock for activated carbon production as they are renewable sources and low cost materials. This study present the optimize conditions for preparation of durian peel activated carbon (DPAC) for removal of methylene blue (MB) from synthetic effluents. The effects of carbonization temperature (from 673K to 923K) and impregnation ratio (from 0.2 to 1.0) with potassium hydroxide KOH on the yield, surface area and the dye adsorbed capacity of the activated carbons were investigated. The dye removal capacity was evaluated with methylene blue. In comparison with the commercial grade carbons, the activated carbons from durian peel showed considerably higher surface area especially in the suitable temperate and impregnation ratio of activated carbon production. Methylene blue removal capacity appeared to be comparable to commercial products; it shows the potential of durian peel as a biomass source to produce adsorbents for waste water treatment and other application. Optimize condition for preparation of DPAC determined by using response surface methodology was at temperature 760 K and IR 1.0 which resulted the yield (51%), surface area (786 m2/g), and MB removal (172 mg/g).


2020 ◽  
Vol 14 (2) ◽  
pp. 168-172
Author(s):  
Marija Milanovic ◽  
Zoran Obrenovic ◽  
Ivan Stijepovic ◽  
Ljubica Nikolic

Boehmite nanocrystalline powders were obtained by neutralization of Bayer liquor at 70?C with addition of glucose. Temperature of the neutralization induced formation of the flower-like morphology of the nanopowders. XRD and FTIR results confirmed that the single phase boehmite is formed without any other impurities. Calcination at 500?C led to the formation of transition -alumina with the retention of the flower-like morphology. Both as-synthesised and calcined powders possessed high specific surface area with mesopores between 3-6 nm in diameter. Relatively low temperature of neutralization as well as the use of low cost and ecologically friendly glucose as a surfactant are very promising for the possible application in the industrial production of alumina nanopowders.


2019 ◽  
Vol 21 (6) ◽  
pp. 3122-3133 ◽  
Author(s):  
Ruben Heimböckel ◽  
Frank Hoffmann ◽  
Michael Fröba

A new capacitor model that confirms the non-constant capacitive contribution of different pore sizes and provides the possibility of simulating the capacitance values of porous carbons.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 765
Author(s):  
Jun-Bin Huang ◽  
Jagabandhu Patra ◽  
Ming-Hsien Lin ◽  
Ming-Der Ger ◽  
Yih-Ming Liu ◽  
...  

We demonstrate a facile and effective method, which is low-cost and easy to scale up, to fabricate holey graphene nanosheets (HGNSs) via ultrafast heating during synthesis. Various heating temperatures are used to modify the material properties of HGNSs. First, we use HGNSs as the electrode active materials for electric double-layer capacitors (EDLCs). A synthesis temperature of 900 °C seems to be optimal, i.e., the conductivity and adhesion of HGNSs reach a compromise. The gravimetric capacitance of this HGNS sample (namely HGNS-900) is 56 F·g−1. However, the volumetric capacitance is low, which hinders its practical application. Secondly, we incorporate activated carbon (AC) into HGNS-900 to make a composite EDLC material. The effect of the AC:HGNS-900 ratio on the capacitance, high-rate performance, and cycling stability are systematically investigated. With a proper amount of HGNS-900, both the electrode gravimetric and volumetric capacitances at high rate charging/discharging are clearly higher than those of plain AC electrodes. The AC/HGNS-900 composite is a promising electrode material for nonaqueous EDLC applications.


2019 ◽  
Vol 10 ◽  
pp. 281-293 ◽  
Author(s):  
Donghui Zheng ◽  
Man Li ◽  
Yongyan Li ◽  
Chunling Qin ◽  
Yichao Wang ◽  
...  

Developing a facile and environmentally friendly approach to the synthesis of nanostructured Ni(OH)2 electrodes for high-performance supercapacitor applications is a great challenge. In this work, we report an extremely simple route to prepare a Ni(OH)2 nanopetals network by immersing Ni nanofoam in water. A binder-free composite electrode, consisting of Ni(OH)2 nanopetals network, Ni nanofoam interlayer and Ni-based metallic glass matrix (Ni(OH)2/Ni-NF/MG) with sandwich structure and good flexibility, was designed and finally achieved. Microstructure and morphology of the Ni(OH)2 nanopetals were characterized. It is found that the Ni(OH)2 nanopetals interweave with each other and grow vertically on the surface of Ni nanofoam to form an “ion reservoir”, which facilitates the ion diffusion in the electrode reaction. Electrochemical measurements show that the Ni(OH)2/Ni-NF/MG electrode, after immersion in water for seven days, reveals a high volumetric capacitance of 966.4 F/cm3 at a current density of 0.5 A/cm3. The electrode immersed for five days exhibits an excellent cycling stability (83.7% of the initial capacity after 3000 cycles at a current density of 1 A/cm3). Furthermore, symmetric supercapacitor (SC) devices were assembled using ribbons immersed for seven days and showed a maximum volumetric energy density of ca. 32.7 mWh/cm3 at a power density of 0.8 W/cm3, and of 13.7 mWh/cm3 when the power density was increased to 2 W/cm3. The fully charged SC devices could light up a red LED. The work provides a new idea for the synthesis of nanostructured Ni(OH)2 by a simple approach and ultra-low cost, which largely extends the prospect of commercial application in flexible or wearable devices.


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