Different failure modes for V-containing and V-free AB(2) metal hydride alloys

作者：Young K^*; Wong D F; Yasuoka S; Ishida J; Nei J; Koch J

来源：Journal of Power Sources, 2014, 251: 170-177.

DOI：10.1016/j.jpowsour.2013.11.035

• Hydrogen absorbing materials
• Transition metal alloys
• Metal hydride electrode
• Electrochemical reactions

Failure modes of a V-containing and a V-free AB(2) Laves phase-based metal hydride alloy were studied by the combination of X-ray diffractometer, scanning electron microscope, X-ray energy dispersive spectroscopy, inductively coupled plasma, Soxhlet extraction, and magnetic susceptibility measurement. Cells with the V-containing alloy exhibited less capacity degradation up until venting occurred in the cells, after which the capacity rapidly degraded. Cells with the V-free alloy remained linear in capacity degradation throughout the cycle life test. The failure mechanism for the V-containing alloy is related to the formation of an oxide layer that penetrates deeper into the alloy particles due to high V leaching and impedes gas recombination, while the failure mechanism for the V-free alloy is related to the continuous pulverization of the main AB2 phase.

• 出版日期2014-4-1