Reaction kinetics and X-ray absorption spectroscopy studies of yttrium-containing metal hydride electrodes
This is a study of electrode degradation mechanisms and 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. X-ray adsorption (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. Allowing with Y decreased the corrosion rate. The results are consistent with corrosion inhibition by a Y-containing passive film. The increase in the exchange current density of the hydrogen oxidation reaction 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., Upton, NY (US)
- Sponsoring Organization:
- US Department of Energy
- DOE Contract Number:
- AC02-98CH10886
- OSTI ID:
- 20001067
- Journal Information:
- Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 10 Vol. 146; ISSN JESOAN; ISSN 0013-4651
- Country of Publication:
- United States
- Language:
- English
Similar Records
REACTION KINETICS AND X-RAY ABSORPTION SPECTROSCOPY STUDIES OF YTTRIUM CONTAINING METAL HYDRIDE ELECTRODES
Synthesis and characterization of metal hydride electrodes. Interim report