Embrittlement of LaNi5-type alloy electrodes during the cathodic evolution of hydrogen

In general, the hydrogen storage alloy electrodes such as LaNi5 were liable to sustain damage owing to hydrogen embrittlement during cathodization. However, such a damage was found to be not serious as far as the hydrogen fugacity, being connected to the cathodic overpotential, was less than the equilibrium hydrogen pressure. Thus, the surface damage can be prevented by controlling the current density and temperature.