The charging efficiencies of MmNi(5), MmNi(4.5)Mn(0.5), MmNi(3.8)Co(0.7)Mn(0.5), ZrV0.6Ni1.4, ZrV0.6Mn0.4Ni1.0, ZrV0.6Mn0.4Co0.2Ni0.8 alloy electrodes (Mm = Mischmetal) are investigated in terms of hydrogen evolution. Experiments an conducted to optimize: (i) elemental composition of the MmNi(5) 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.