Reaction kinetics and x-ray absorption spectroscopy studies of yttrium containing metal hydride electrodes
- Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science
This was a study of electrode degradation mechanisms and the reaction kinetics of LaNi{sub 4.7}Sn{sub 0.3}, La{sub (1{minus}x)} Y{sub x}Ni{sub 4.7}Sn{sub 0.3} (x = 0.1, 0.2, and 0.3) and La{sub 0.7}Y{sub 0.3}Ni{sub 4.6}Sn{sub 0.3}Co{sub 0.1} metal hydride electrodes. Alloy characterization included x-ray diffraction (XRD), x-ray absorption (XAS), hydrogen absorption in a Sieverts apparatus, and electrochemical cycling of alloy electrodes. The atomic volume of H was determined for two of the alloys. Electrochemical kinetic measurements were made using steady state galvanostatic measurements, galvanodynamic sweep, and electrochemical impedance techniques. XAS was used to examine the degree of corrosion of the alloys with cycling. Alloying with Y decreased the corrosion rate. The results are consistent with corrosion inhibition by a Y containing passive film. The increase in the kinetics of the hydrogen oxidation reaction (HOR) with increasing depth of discharge was much greater on the Y containing alloys. This may be due to the dehydriding of the catalytic species on the surface of the metal hydride particles.
- Research Organization:
- Brookhaven National Lab., Dept. of Applied Science, Upton, NY (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC02-98CH10886
- OSTI ID:
- 354897
- Report Number(s):
- BNL--66600; CONF-981108--; ON: DE99003359; BR: KC030204
- Country of Publication:
- United States
- Language:
- English
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