Effect of magnetron sputtering of active powder with Fe-Cr-Ni layers on electrochemical parameters of metal hydride electrode

Particles of hydrogen storage, LaNi4.5Co0.5 powdered material have been encapsulated with thin (about 40 nm) Fe-Cr-Ni layers using magnetron sputtering method. The acid resistant, 1.4301 (EN 10088) stainless steel has been applied as a target. The effect of powder encapsulation on galvanostatic charge/discharge characteristics (hydride capacity, exchange current density of the H2O/H-2 system, susceptibility to oxidation) for the modified hydride electrodes has been evaluated. The plots of discharge curves testify to limitation of active material tendency to working surface development. The material modified reveals comparatively high discharge capacities which should be attributed to inhibition of oxidation processes of active material by the surface layers formed. The powder sputtering does not worsen the kinetics of charge/discharge processes for modified electrode.