TOKYO – Toyota Motor Corp. is counting on a huge reduction in the cost of fuel-cell stacks as it makes a bid to market a fuel-cell vehicle in 2015.
In addition to targeting a 90% cut in cost over the next six years, the auto maker is looking for a 50%-100% increase in power density and stack durability and a wide operating temperature band from -22º F to 221º F (-30º C to 105º C). Toyota also wants to reduce platinum use to 90% of current levels.
In announcing the goal to retail an FCV in 2015, Yoshihiko Masuda, managing officer in charge of Toyota’s fuel-cell program, declines to reveal first-year volume targets or the precise segment of the market in which the vehicle will compete. However, company sources indicate the technology likely will be applied first to long-haul trucks and buses.
Toyota began leasing FCVs (mostly Highlander cross/utility vehicles and city buses) in 2002 and so far has placed more than 60 into operation in Japan and the U.S. Included are eight buses operating in Aichi prefecture. Another 14 units are planned for 2009.
Masuda says Toyota will reduce tank costs by employing a thinner carbon-fiber layer and simplifying valve and regulator design.
Concurrently, researchers are working to extend fuel-cell life to 125,000 miles (201,000 km) by making improvements in the electrolyte membrane, separator and gas-diffusion layer of the stack.
The executive notes Toyota already has achieved low-temperature operation to -44º F (-37º C), in part through use of super-cooled water in the stack. The auto maker also has exceeded its planned 400-mile (644-km) driving range by more than 100 miles (161 km).
In a driving test last June from Osaka to Tokyo, a pair of Highlander-based FCHV-adv vehicles completed the 350-mile (563-km) trip with enough fuel left in their 5.5-cu.-ft. (156 L) high-pressure tanks to go another 150 miles (241 km), thus a net of 500 miles (805 km).
Masuda credits the longer range – up from 206 miles (332 km) – to improvements in the fuel-cell system and an almost doubling of fuel-tank capacity achieved in part by raising pressure levels from 5,075 psi (350 bar) to 10,150 psi (700 bar).
| Powertrain | Well-to-Tank | Tank-to-Wheel | Well-to-Wheel |
|---|---|---|---|
| Fuel Cell | 67 | 59 | 40 |
| Electric Vehicle | 39 | 85 | 33 |
| Gas-Electric Hybrid | 84 | 40 | 34 |
| Gasoline-Vehicle | 84 | 23 | 19 |
| Source: Toyota | |||
Meanwhile, fuel economy was improved 25% by reducing auxiliary system loss and increasing regenerative energy, he says.
Among the areas the auto maker says it already has made improvements: driving energy, inverter motor loss, high-voltage converter loss, fuel cell heat loss, air-compressor power, hydrogen pump power, cooling water power and auxiliary battery power.
The Toyota executive discloses a new set of well-to-tank, tank-to-wheel and well-to-wheel figures showing fuel cells, both onboard reforming and compressed hydrogen types, outperforming other powertrains in energy efficiency, with a 40% well-to-wheel rating.
