Preparation of a nickel–metal hydride (Ni–MH) rechargeable battery and its application to a solar vehicle

This paper reports the preparation of a nickel–metal hydride (Ni–MH) rechargeable battery with a high capacity of 96 V-14 Ah and a high energy density of 1.4 kWh. The negative electrode was prepared with a rare earth based MmNi5 type hydrogen storage alloy and graphite as a conductive material. The prepared Ni–MH battery was installed into a solar vehicle. The data obtained from a three-day long world solar car rally yielded high discharge-to-charge coulomb efficiency (76%) and solar-to-electric energy conversion efficiency (60%) in average, in spite of severe rally conditions.