Charging efficiency of metal-hydride electrodes

The charging efficiencies of MmNi5, MmNi4.5Mn0.5, MmNi3.8Co0.7Mn0.5, ZrV0.6Ni1.4, ZrV0.6Mn0.4Ni1.0, ZrV0.6Mn0.4Co0.2Ni0.8 allay electrodes (Mm = Mischmetal) are investigated in terms of hydrogen evolution. Experiments are conducted to optimize: (i) elemental composition of the MmNi5 system and Zr-based Laves-phase hydrogen storage alloys; (ii) additive materials, such as cobalt powder, nickel powder, Teflonized carbons, and acetylene black; (iii) the proportion of the additives in the alloy; (iv) the best percentage of the composite additives in the metal-hydride electrodes. The results show that the electrode activation, charging efficiency and high-rate discharge depend greatly on the active materials, as well as the type and the amount of the additives in the electrodes.