Asymmetric deposition of manganese oxide in single walled carbon nanotube films as electrodes for flexible high frequency response electrochemical capacitors
Manganese oxide (MnO2) is a promising pseudocapacitive electrode material because of its high capacitance, abundant resource, low-cost, and environmental friendliness. However, its poor electrical and ionic conductivities and low stability hinder applications. Forming MnO2 nanocomposites with high s...
| Main Authors: | , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2013
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| Online Access: | https://hdl.handle.net/10356/95859 http://hdl.handle.net/10220/10845 |
| _version_ | 1826110119580008448 |
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| author | Shen, Jianmin Liu, Andong Tu, Yu Wang, Hong Jiang, Rongrong Ouyang, Jie Chen, Yuan |
| author2 | School of Chemical and Biomedical Engineering |
| author_facet | School of Chemical and Biomedical Engineering Shen, Jianmin Liu, Andong Tu, Yu Wang, Hong Jiang, Rongrong Ouyang, Jie Chen, Yuan |
| author_sort | Shen, Jianmin |
| collection | NTU |
| description | Manganese oxide (MnO2) is a promising pseudocapacitive electrode material because of its high capacitance, abundant resource, low-cost, and environmental friendliness. However, its poor electrical and ionic conductivities and low stability hinder applications. Forming MnO2 nanocomposites with high surface area porous metal, carbon materials, or conducting polymers is a possible solution. In this work, we have developed a facile and scalable asymmetric in situ deposition method to incorporate MnO2 nanoparticles in conductive single walled carbon nanotube (SWCNT) films. The high porosity of vacuum filtrated SWCNT films accommodates pseudocapacitive MnO2 nanoparticles without sacrificing the mechanical flexibility and electrochemical stability of SWCNT films. We exposed one side of SWCNT films to acidic potassium permanganate (KMnO4) solution. The infiltrated KMnO4 solution partially etches SWCNTs to create abundant mesopores, which ensure electrolyte ions efficiently access deposited MnO2. Meanwhile, the remaining SWCNT network serves as excellent current collectors. The electrochemical performance of the SWCNT–MnO2 composite electrodes depends on the porosity of SWCNT films, pH, and concentration of KMnO4 solution, deposition temperature and time. Our optimized two-electrode electrochemical capacitor, with 1 M Na2SO4 in water as electrolyte, showed a superior performance with specific capacitance of 529.8 F g−1, energy density of 73.6 Wh kg−1, power density of 14.6 kW kg−1, excellent capacitance retention (99.9%) after 2000 charge and discharge cycles, and one of the highest reported frequency responses (knee frequency at 1318 Hz). The high performance flexible electrochemical capacitors have broad applications in portable electronics and electrical vehicles, especially when high frequency response is desired. |
| first_indexed | 2024-10-01T02:29:12Z |
| format | Journal Article |
| id | ntu-10356/95859 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T02:29:12Z |
| publishDate | 2013 |
| record_format | dspace |
| spelling | ntu-10356/958592020-03-07T11:35:35Z Asymmetric deposition of manganese oxide in single walled carbon nanotube films as electrodes for flexible high frequency response electrochemical capacitors Shen, Jianmin Liu, Andong Tu, Yu Wang, Hong Jiang, Rongrong Ouyang, Jie Chen, Yuan School of Chemical and Biomedical Engineering Manganese oxide (MnO2) is a promising pseudocapacitive electrode material because of its high capacitance, abundant resource, low-cost, and environmental friendliness. However, its poor electrical and ionic conductivities and low stability hinder applications. Forming MnO2 nanocomposites with high surface area porous metal, carbon materials, or conducting polymers is a possible solution. In this work, we have developed a facile and scalable asymmetric in situ deposition method to incorporate MnO2 nanoparticles in conductive single walled carbon nanotube (SWCNT) films. The high porosity of vacuum filtrated SWCNT films accommodates pseudocapacitive MnO2 nanoparticles without sacrificing the mechanical flexibility and electrochemical stability of SWCNT films. We exposed one side of SWCNT films to acidic potassium permanganate (KMnO4) solution. The infiltrated KMnO4 solution partially etches SWCNTs to create abundant mesopores, which ensure electrolyte ions efficiently access deposited MnO2. Meanwhile, the remaining SWCNT network serves as excellent current collectors. The electrochemical performance of the SWCNT–MnO2 composite electrodes depends on the porosity of SWCNT films, pH, and concentration of KMnO4 solution, deposition temperature and time. Our optimized two-electrode electrochemical capacitor, with 1 M Na2SO4 in water as electrolyte, showed a superior performance with specific capacitance of 529.8 F g−1, energy density of 73.6 Wh kg−1, power density of 14.6 kW kg−1, excellent capacitance retention (99.9%) after 2000 charge and discharge cycles, and one of the highest reported frequency responses (knee frequency at 1318 Hz). The high performance flexible electrochemical capacitors have broad applications in portable electronics and electrical vehicles, especially when high frequency response is desired. 2013-07-01T04:41:00Z 2019-12-06T19:22:25Z 2013-07-01T04:41:00Z 2019-12-06T19:22:25Z 2012 2012 Journal Article Shen, J., Liu, A., Tu, Y., Wang, H., Jiang, R., Ouyang, J., et al. Asymmetric deposition of manganese oxide in single walled carbon nanotube films as electrodes for flexible high frequency response electrochemical capacitors. Electrochimica Acta, 78, 122-132. 0013-4686 https://hdl.handle.net/10356/95859 http://hdl.handle.net/10220/10845 10.1016/j.electacta.2012.05.138 en Electrochimica acta © 2012 Elsevier Ltd. |
| spellingShingle | Shen, Jianmin Liu, Andong Tu, Yu Wang, Hong Jiang, Rongrong Ouyang, Jie Chen, Yuan Asymmetric deposition of manganese oxide in single walled carbon nanotube films as electrodes for flexible high frequency response electrochemical capacitors |
| title | Asymmetric deposition of manganese oxide in single walled carbon nanotube films as electrodes for flexible high frequency response electrochemical capacitors |
| title_full | Asymmetric deposition of manganese oxide in single walled carbon nanotube films as electrodes for flexible high frequency response electrochemical capacitors |
| title_fullStr | Asymmetric deposition of manganese oxide in single walled carbon nanotube films as electrodes for flexible high frequency response electrochemical capacitors |
| title_full_unstemmed | Asymmetric deposition of manganese oxide in single walled carbon nanotube films as electrodes for flexible high frequency response electrochemical capacitors |
| title_short | Asymmetric deposition of manganese oxide in single walled carbon nanotube films as electrodes for flexible high frequency response electrochemical capacitors |
| title_sort | asymmetric deposition of manganese oxide in single walled carbon nanotube films as electrodes for flexible high frequency response electrochemical capacitors |
| url | https://hdl.handle.net/10356/95859 http://hdl.handle.net/10220/10845 |
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