Although fuel cell vehicles have great potential as future vehicles, it is also realized that further breakthrough technologies to solve essential problems, such as cost and cruising range to be competitive with internal combustion engine vehicles. We have developed a new type of hydrogen-absorbing alloy tank. The high-pressure metal hydride (MH) tank is designed, based on the 35 MPa cylinder vessel. The heat-exchanger module including hydrogen-absorbing alloy is integrated in the tank. Its advantage over high-pressure cylinder vessel is large hydrogen storage capacity, for example, 7.3 kg at the 180 L tank volume. Cruising range is about 2.5 times longer than that of the same volume 35 MPa cylinder vessel system.
   While the conventional hydrogen-absorbing alloy tank has problems in charge and discharge process, the hydrogen charging rate of this system is equal to 35 MPa cylinder without external cooling facility. Furthermore, the hydrogen-absorbing alloy, Ti-Cr-Mn with AB2 laves phase can release hydrogen at 243 K. Its dissociation pressure at 243 K is 0.5 MPa.
   High-pressure MH system shows a realistic way to obtain adequate cruising range over 700 km. To develop a practical hydrogen tank for fuel cell vehicles, estimated target of hydrogen storage capacity of alloys is 3-4 mass% and 1600-2400 times as volumetric density.