Fig. 1 is a schematic view showing the structure of a large-sized Ni–MH battery, called the GIGACELL [2,3]. The GIGACELL-type single cells with 750 mA h–205 A h ratings were constructed using the Co-free electrodes. Inside the cells, pre-formed stripes of positive and negative electrodes are inserted into the respective sides of the pleat-folded separator. The negative alloy (MmNi3.7Co0.7Mn0.3Al0.3) was used as the reference for the comparison. The composition was similar to that used for the conventional GIGACELL, mainly emphasizing the power performance. The capacity ratio was calculated to be N/P = 2.5. The electrolyte was 4.8 mol/LKOH + 1.2 mol/L-NaOH.