Various ways including substitution and protection used to improve the cyclability of ‘MgNi' electrodes

Mathieu Pasturel (1) , Jean-Louis Bobet (1) , Bernard Chevalier (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Three different treatments have been investigated to improve the cyclability in KOH electrolyte of ‘MgNi' used as hydrogen storage electrode material for Ni–MH batteries. Whereas hydrophobic molecule grafting does not give significant improvement, replacement of Mg by Ti or coating the ‘MgNi' powder with copper in a supercritical CO2–EtOH mixture increase strongly the resistance of the electrode against hydroxylation: the capacity after 12 cycles is 98% higher for ‘Mg0.5Ti0.5Ni' and 45% higher after coating by a thin copper film in comparison with the raw ‘MgNi' material.

Mots clés: Mechanical grinding; Electrochemistry; ‘MgNi' electrodes; Coating; Supercritical fluid

Domaines: Matériaux

Mathieu Pasturel, Jean-Louis Bobet, Bernard Chevalier. Various ways including substitution and protection used to improve the cyclability of ‘MgNi' electrodes. Journal of Alloys and Compounds, 2003, 356-357, pp.764-767. ⟨10.1016/S0925-8388(03)00250-0⟩. ⟨hal-00189362⟩