Corrosion degradation of powder composite hydride electrodes in conditions of long-lasting cycling

The LaNi4.5Co0.5 hydrogen storage material degradation process in 6 M KOH solution fulfills first-order chemical reaction kinetic law. After ca 10 first cycles, up to N = 45 cycle, the logarithm of discharge capacity linearly decreases with cycle number. The slope of logQdisch = f(N) straight lines is a measure of degradation rate constant (kdegr). Corrosion rate of the tested material is directly proportional to kdegr. The LaNi4.5Co0.5 powder encapsulation with electroless Ni-P is prone to evident increase of the hydride electrode corrosion resistance. Additionally, encapsulation improves the charge/discharge kinetics: the exchange currents of H2O/H2 system are 20% greater for the chemically treated powder.