F. Meli et al., EFFECT OF SILICON ON THE PROPERTIES OF AB5-BASED ALLOYS FOR BATTERY ELECTRODE APPLICATION, Zeitschrift für physikalische Chemie, 183, 1994, pp. 371-377
Citations number
13
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
Because of their rather low hydrogen storage capacity LaNi5-xSix-alloy
s have not been studied and have not been considered for battery appli
cations so far. We have found, however, that the alloy LaNi4.5Si0.5 sh
ows fast activation and incredibly high stability upon electrochemical
cycling (-0.07 mAh/g/cycle) with fairly high electrochemical capacity
(245 mAh/g). This positive effect of silicon was also found in combin
ation with aluminium in (La,Lm,Mm)(Ni,Si,Al)5 alloys where, however, t
he hydrogen storage capacity was quite low. Heat treatments of LaNi4.7
Si0.3 showed only minor effects on the cyclic stability. PCT, XPS and
electrochemical measurements were carried out on (La,Lm,Mm)(Ni,Si,Al)5
alloys. Electrochemical cycling in 6 M KOH electrolyte forms a sublay
er rich in metallic nickel the rare earth probably beeing dissolved in
the electrolyte. Contrary to earlier suggestions no passivating silic
on or aluminium surface oxide film could be found on cycled electrodes
.