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Stable ionic-liquid...
Stable ionic-liquid-based symmetric supercapacitors from Capsicum seed-porous carbons
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- Momodu, Damilola (author)
- Universiteit van Pretoria,University of Pretoria
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- Sylla, Ndeye Fatou (author)
- Universiteit van Pretoria,University of Pretoria
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- Mutuma, Bridget (author)
- Universiteit van Pretoria,University of Pretoria
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- Bello, Abdulhakeem (author)
- African University of Science and Technology (AUST),Universiteit van Pretoria,University of Pretoria
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- Masikhwa, Tshifhiwa (author)
- Universiteit van Pretoria,University of Pretoria
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- Lindberg, Simon, 1987 (author)
- Chalmers tekniska högskola,Chalmers University of Technology
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- Matic, Aleksandar, 1968 (author)
- Chalmers tekniska högskola,Chalmers University of Technology
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- Manyala, Ncholu (author)
- Universiteit van Pretoria,University of Pretoria
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(creator_code:org_t)
- Elsevier BV, 2019
- 2019
- English.
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In: Journal of Electroanalytical Chemistry. - : Elsevier BV. - 1572-6657. ; 838, s. 119-128
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https://doi.org/10.1...
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Abstract
Subject headings
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- In this study, a symmetric ionic-liquid based supercapacitor was assembled with porous carbon derived from Capsicum (bell pepper) seeds. The “peppered”-activated carbon (ppAC) was synthesized using varying amounts of KHCO 3 activating agent (AA) at 850 °C carbonization temperature. The best device performance reported was recorded with optimum amounts of AA to raw material. The need for less amount of AA is crucial if the entire activation/carbonization process is to be scaled-up with the cost and final product yield also being important for a viable synthesis. A mechanism of saturation of pores with unreacted AA which leads to lower porosity metrics in the samples with increasing the amount of AA during carbonization/activation was also proposed. Using an ionic liquid electrolyte, 1-ethyl-3-methylimidazolium bistrifluorosulfonylimide (EMIM-TFSI), the ppAC-based supercapacitor operated up to a maximum cell voltage of 3.20 V. A specific energy of 37 Wh kg −1 was obtainable with a corresponding practical power density of 0.6 kW kg −1 at 0.5 A g −1 . A specific energy of ∼26 Wh kg −1 was still achievable when the applied current was doubled to 1.0 A g −1 and a high cyclic stability (approx. 99% coulombic efficiency) was proven over 25,000 cycles. Further ageing test performed on the device revealed a remarkable improvement in the electrochemical performance after a 180 h (ca. 1 week) floating time. The obtained results also confirmed a uniquely distributed porous carbon in which the complete utilization of the entire less-corrosive KHCO 3 AA for optimal pore activation at elevated carbonization temperatures. Thus, the efficient design combinations for stable, high-energy and power ionic liquid-based supercapacitors with cheaper biomass-based materials are demonstrated.
Subject headings
- TEKNIK OCH TEKNOLOGIER -- Kemiteknik -- Kemiska processer (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Chemical Engineering -- Chemical Process Engineering (hsv//eng)
- NATURVETENSKAP -- Kemi -- Materialkemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Materials Chemistry (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Kemiteknik -- Annan kemiteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Chemical Engineering -- Other Chemical Engineering (hsv//eng)
- NATURVETENSKAP -- Fysik -- Annan fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Other Physics Topics (hsv//eng)
Keyword
- Ionic electrolyte
- Cyclic stability
- Nanoporous carbons
- High specific energy
- Biomass waste
Publication and Content Type
- art (subject category)
- ref (subject category)
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