Electrochemical investigations on cobalt-microencapsulated MmNi2.38Al0.82Co0.66Si0.77Fe0.13Mn0.24 hydrogen storage alloys for Ni–MH batteries
| Autor: | M.V. Ananth, N.G. Renganathan, K. Manimaran, G. Nithya, M. Raju, M. Ganesan |
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| Rok vydání: | 2010 |
| Předmět: |
inorganic chemicals
Materials science Renewable Energy Sustainability and the Environment Hydride Alloy Metallurgy technology industry and agriculture Energy Engineering and Power Technology chemistry.chemical_element Activation energy engineering.material equipment and supplies Condensed Matter Physics Electrochemistry Hydrogen storage Fuel Technology Chemical engineering chemistry Coating Electrode engineering Cobalt |
| Zdroj: | International Journal of Hydrogen Energy. 35:4630-4637 |
| ISSN: | 0360-3199 |
| DOI: | 10.1016/j.ijhydene.2010.02.045 |
| Popis: | Cobalt coatings were applied over lanthanum process-rich MmNi 2.38 Al 0.82 Co 0.66 Si 0.77 Fe 0.13 Mn 0.24 alloy particles by an autocatalytic electroless deposition process. Electrode characteristics such as electrochemical capacity and cycle life were studied for the uncoated and coated alloys. The structure and morphology of the surface modified samples were characterized with XRD and SEM/EDAX techniques. The cobalt coating forms a thin layer on the surface of the core material and the coated alloys exhibit a 15% improvement in performance over the bare alloy. A comparison of the electrochemical impedance behaviour of the bare and cobalt-coated metal hydride electrodes at different states-of-charge reveals that the relaxation period is distinct for different SOCs. The cobalt microencapsulations influence the apparent activation energy of the dehydriding process. The calculated equivalent rate constant ( k eq ) values confirm the improvement in reversibility for the cobalt-coated alloy as compared to the bare alloy. |
| Databáze: | OpenAIRE |
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