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Fabrication of Core-Shell Fe3O4@C@MnO2 Microspheres and Their Application in Supercapacitors
- Source :
- Journal of the Electrochemical Society; January 2018, Vol. 165 Issue: 2 pE58-E63, 6p
- Publication Year :
- 2018
-
Abstract
- Core-shell Fe3O4@C@MnO2 microspheres were fabricated using multi-step solution-phase interface deposition. Fe3O4 nanoparticles were coated with SiO2 via the Stober method and further covered with resorcinol and formaldehyde (RF) resins. Fe3O4@C nanoparticles with inter-lamellar void were obtained by carbonizing RF under N2, and etching SiO2 with NaOH. These nanoparticles served as template and were further coated with MnO2 shell to prepare Fe3O4@C@MnO2 microspheres. The resultant composites showed a typical core-shell structure with distinct magnetite core, 10 nm inter-lamellar void, a 30 nm thick carbon layer in the middle layer, and a 50 nm thick MnO2 shell at the outer layer. Fe3O4@C@MnO2 microspheres served as supercapacitor electrode materials. The electrochemical performance of the Fe3O4@C@MnO2 electrode was investigated using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge. Fe3O4@C@MnO2 electrode showed a specific capacitance of 158 F g[?]1 at 0.5 A g[?]1 and outstanding cycle stability with 89.7% capacitance retention after 2000 cycles. By contrast, the specific capacitance of Fe3O4@C electrode was 117 F g[?]1 at 0.5 A g[?]1 exhibited and only 75.2% capacitance retention after 2000 cycles. Thus, Fe3O4@C@MnO2 microspheres had great potential in supercapacitor applications in the future.
Details
- Language :
- English
- ISSN :
- 00134651 and 19457111
- Volume :
- 165
- Issue :
- 2
- Database :
- Supplemental Index
- Journal :
- Journal of the Electrochemical Society
- Publication Type :
- Periodical
- Accession number :
- ejs52677693