Abstract
Al-substituted α-cobalt hydroxide was prepared by a potentiostatic deposition process at -1.0 V (vs. Ag/AgCl) onto stainless steel electrodes by using a mixed aqueous solution of cobalt nitrate and aluminum nitrate. Their structure and surface morphology were studied by using X-ray diffraction analysis, energy dispersive X-ray spectroscopy and scanning electron microscopy. The SEM images showed changes in the nanostructure of α-cobalt hydroxide by the addition of Al. Galvanostatic charge-discharge curves showed a drastic improvement in the capacitive characteristics of α-cobalt hydroxide, with a specific energy increase from 11.3 to 18.7 Wh kg-1 by the substitution of just 8 at.% Al, and a specific capacitance of 843 F g-1 between 0 and 0.4 V. The cycle stability data suggest no significant changes in the discharge characteristics of α-cobalt hydroxide by the addition of Al.
Original language | British English |
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Pages (from-to) | 685-689 |
Number of pages | 5 |
Journal | Journal of Power Sources |
Volume | 177 |
Issue number | 2 |
DOIs | |
State | Published - 1 Mar 2008 |
Keywords
- Aluminum hydroxide
- Cobalt hydroxide
- Potentiostatic deposition
- Specific capacitance
- Supercapacitor