Effect of Ce composition on the structural and electronic characteristics of some metal hydride electrodes: A XANES and EXAFS investigation
- Brookhaven National Lab., Upton, NY (United States)
- Texas A and M Univ., College Station, TX (United States). Center for Electrochemical Systems and Hydrogen Research
Substitution of the B component in the prototype AB{sub 5} type (LaNi{sub 5}) metal hydride alloys have resulted in their increased acceptance as anodes for rechargeable alkaline batteries. Recently substitution of the A component (La) for imparting properties such as increased corrosion resistance has received attention. This investigation deals with the role of Ce as a substituent for the La and its effect in terms of corrosion resistance. The alloys chosen have the general composition of La{sub x}Ce{sub 1-x}B{sub 5} (x = 1, 0.8, 0.5 and 0.25) where B is Ni{sub 3.55}CO{sub 0.75}Mn{sub 0.4}Al{sub 0.3} together with alloys containing the mischmetal (Mm) as the A component (both synthetic and commercial). Electrochemical cycling results show that Ce lowers the capacity loss in the alloys and that this effect is not a simple function of the extent of lattice expansion during hydriding as was previously suggested. Correlation of the electrochemical and XAS results show that capacity loss is directly related to the extent of Ni corrosion. Effect of Ce substitution seems to result in a stable Ce oxide hydroxide coating which imparts the corrosion resistance.
- Research Organization:
- Brookhaven National Lab., Upton, NY (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 110799
- Report Number(s):
- BNL--60541; CONF-941063--14; ON: DE96000426
- Country of Publication:
- United States
- Language:
- English
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