کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1613440 | 1005597 | 2013 | 5 صفحه PDF | دانلود رایگان |
• Failure modes of NiMH battery with AB5 and A2B7 alloys were reported.
• Stable gamma-NiOOH was formed with the incorporation of Al from negative electrode.
• The formation of gamma-NiOOH caused capacity degradation in AB5-containing battery.
• Pulverization of the main A2B7 phase is the main failure mode for A2B7-containing battery.
The failure modes of nickel/metal hydride batteries made from conventional AB5 and La-only Mg-containing A2B7 metal hydride alloys were studied at the end of 70% state-of-charge cycle life testing (reaching below 3.1 Ah capacity in a 5.5 Ah design cell) by the combination of inductively coupled plasma, scanning electron microscope, X-ray energy dispersive spectroscopy and composition mapping, and X-ray diffraction analysis. The capacity degradation of cell with AB5 alloy was found to have been caused by the combination of metal hydride alloy oxidation and non-reversible γ-NiOOH phase formation, which was promoted by the incorporation of Al leached out from the oxidation product of the Al-containing negative electrode. In the cell with Al-free A2B7 alloy, the end of cycle life was the result of pulverization in the main A2B7 phase.
Journal: Journal of Alloys and Compounds - Volume 580, Supplement 1, 15 December 2013, Pages S373–S377