In situ investigation of commercial Ni(OH)(2) and LaNi5-based electrodes by neutron powder diffraction
Artikel i vetenskaplig tidskrift, 2015

Electrochemical reactions at both positive and negative electrodes in a nickel metal hydride (Ni-MH) battery during charge have been investigated by in situ neutron powder diffraction. Commercially available beta-Ni(OH)(2) and LaNi5-based powders were used in this experiment as positive and negative electrodes, respectively. Exchange of hydrogen by deuterium for the beta-Ni(OH)(2) electrode was achieved by ex situ cycling of the cell prior to in situ measurements. Neutron diffraction data collected in situ show that the largest amount of deuterium contained at the positive electrode is de-intercalated from the electrode with no phase transformation involved up to similar to 100 mA h/g and, in addition, the 110 peak width for the positive electrode increases on charge. The negative electrode of composition MmNi(3.6)Al(0.4)Mn(0.3)Co(0.7), where Mm = Mischmetal, exhibits a phase transformation to an intermediate hydride gamma phase first and then to the beta phase on charge. Unit cell dimensions and phase fractions have been investigated by Rietveld refinement of the crystal structure.

Författare

J. J. Biendicho

Stockholms universitet

Rutherford Appleton Laboratory

M. Roberts

Uppsala universitet

D. Noreus

Stockholms universitet

U. Lagerqvist

Nilar Svenska AB

R. I. Smith

Rutherford Appleton Laboratory

G. Svensson

Stockholms universitet

Stefan Norberg

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Sten Eriksson

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

S. Hull

Rutherford Appleton Laboratory

Journal of Materials Research

0884-2914 (ISSN)

Vol. 30 407-416

Ämneskategorier

Materialteknik

DOI

10.1557/jmr.2014.317