Toyota Develops High-pressure Hydrogen Tanks for Fuel Cell Vehicles

Press Release

TOYOTA MOTOR CORPORATION (TMC) announced today that it has developed 35MPa and 70MPa high-pressure hydrogen tanks for use in fuel cell vehicles. Both tanks have been certified by the High Pressure Gas Safety Institute of Japan*1 — the 35MPa tank in April of last year and the 70MPa tank this past January. Additionally, this April, the 35MPa tank met the above institute's technical standard for compressed hydrogen automobile fuel tanks*2, allowing it to be used for 15 years, compared to three years for previous tanks.

The new Toyota high-pressure hydrogen tanks employ an anti-leak liner made of high-strength nylon resin with superior hydrogen permeation-prevention performance. The tanks also feature an all-composite structure concealed by a carbon fiber exterior, making them light and extremely strong.

The use of a nylon resin tank liner allows the liner to be thinner, meaning that the new 35MPa tank can hold 10% more hydrogen than the same-exterior-size 35MPa tank Toyota used before. This extends the cruising range of Toyota's hydrogen-fueled TOYOTA FCHV fuel cell hybrid passenger vehicle from 300km to 330km in the 10-15 Japanese test cycle. Furthermore, the 70MPa tank, also designed and sized for the TOYOTA FCHV, can store approximately 1.7 times more hydrogen than the previous 35MPa tank, resulting in a cruising range of more than 500km in the 10-15 Japanese test cycle.

Both tanks feature a high-pressure valve developed anew within the Toyota Group. This valve follows a new design that positions a solenoid shut-off valve inside the tank for increased reliability.

Since setting out to develop fuel cell vehicles, Toyota has been independently developing all major fuel cell system components, including the all-important electricity-producing fuel cell stack. In December 2002, Toyota was the first to commercialize a fuel cell vehicle, the TOYOTA FCHV, when it began limited marketing in Japan and the U.S. Since then, 11 TOYOTA FCHVs have been leased in Japan and five in the U.S. Toyota is also active in applying its fuel cell technology to buses-in addition to conducting real-world verification tests with a fuel cell bus prototype operating within Tokyo's metropolitan public bus system (from August 2003 to December 2004), Toyota currently has eight units of its FCHV-BUS transporting visitors between various venues at the EXPO 2005, Aichi, Japan.

Among the numerous issues such as cost and others that need to be solved to allow fuel cell vehicles to become widespread, Toyota views the development of hydrogen storage technology for achieving sufficient cruising range to be to a key issue. As such, in addition to the use of high-pressure tanks, it is continuing research and development of other hydrogen storage methods.

Technical details of the newly developed high-pressure hydrogen tanks for fuel cell vehicles will be disclosed at the 2005 JSAE Annual Congress (Spring) to be held at the Pacifico Yokohama complex from May 18.

*1 An institute under the jurisdiction of the Ministry of Economy, Trade and Industry in charge of certifying high-pressure tanks
*2 Established in March by the above institute as a high-pressure hydrogen safety standard