Advanced supercapacitor prototype using nanostructured double-sided MnO2/CNT electrodes on flexible graphite foil
| Autor: | Mesut Yilmaz, Serkan Akbulut, S. H. Hsu, Weng Poo Kang, Supil Raina |
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| Rok vydání: | 2017 |
| Předmět: |
Supercapacitor
Materials science General Chemical Engineering Nanotechnology 02 engineering and technology Carbon nanotube Current collector 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Capacitance 0104 chemical sciences law.invention law Electrode Materials Chemistry Electrochemistry Specific energy Graphite Composite material 0210 nano-technology FOIL method |
| Zdroj: | Journal of Applied Electrochemistry. 47:1035-1044 |
| ISSN: | 1572-8838 0021-891X |
| DOI: | 10.1007/s10800-017-1098-6 |
| Popis: | Development of advanced supercapacitors which provide greater energy density while retaining high power density can revolutionize energy storage solutions for both civilian and military applications. Herein, we present fabrication and characterization of nanostructured supercapacitor electrodes using manganese dioxide and carbon nanotubes (MnO2/CNTs) on flexible graphite foil substrate for integration into a supercapacitor prototype cell, without any additives or binders. Low-cost, thermal chemical vapor deposition process in a tube furnace was used to synthesize CNTs, acting as the current conductors, directly on both sides of the flexible, conducting graphite foil current collector. Thin-film MnO2 deposition on the CNTs was achieved by electrochemical technique using in situ reduction of potassium permanganate (KMnO4), without any supporting electrolyte, which provides excellent bonding between the two for enhanced stability. Eight electrodes were assembled in a stack with polypropylene separators and packaged in a pouch cell with organic electrolyte (1 M tetraethylammonium tetrafluoroborate in acetonitrile) yielding a total capacitance of nearly 2.8 F at 2.5 V and a corresponding specific capacitance of 388 F g−1 was calculated for MnO2. High cell capacitance and a low DC resistance yield a maximum specific power value of 36.1 kW kg−1 and a maximum specific energy of 48.5 Wh kg−1 at 2.5 V when considering the total mass including that of CNTs and MnO2. Cycling data showed nearly 100% capacitance retention over 3000 charge discharge cycles. To the best of our knowledge, a supercapacitor prototype cell in this configuration has not been fabricated and/or reported previously. Schematic representation of the prototype supercapacitor cell consisting of a stack of eight electrodes with polypropylene separators. On the right is a blow-up representation of a double side electrode with MnO2/CNT on both sides of the graphite foil substrate. The equivalent circuit diagram can be seen on the left, consisting of seven capacitors in parallel |
| Databáze: | OpenAIRE |
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