Degradation mechanisms of high-energy bipolar nickel metal hydride battery with AB(5) and A(2)B(7) alloys

作者：Zhou X; Young K^*; West J; Regalado J; Cherisol K

来源：Journal of Alloys and Compounds, 2013, 580: S373-S377.

DOI：10.1016/j.jallcom.2013.03.014

• Hydrogen absorbing materials
• Metal hydride electrode
• Electrochemical reactions
• Failure mode

The failure modes of nickel/metal hydride batteries made from conventional AB(5) and La-only Mg-containing A(2)B(7) 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 Xray diffraction analysis. The capacity degradation of cell with AB(5) alloy was found to have been caused by the combination of metal hydride alloy oxidation and non-reversible gamma-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 A(2)B(7) alloy, the end of cycle life was the result of pulverization in the main A(2)B(7) phase.

• 出版日期2013-12-15