Europe's biggest carmaker has been researching the fuel cell for more than seven years and claims the high-temperature cell can run more efficiently, with less environmental impact, than the more common low-temperature gas cell.

"We believe that the future belongs to the high-temperature gas cell. The low-temperature gas cell hardly can compare when it comes to mass production," said Juergen Leohold, head of Volkswagen's corporate research. He added that the new cell "will make the overall system in the car lighter, more compact, stable and cheaper."

The high-temperature fuel cell, or HTFC, differs because it is lighter, smaller and could be used in vehicles ranging from a subcompact car to a truck.

"Those are the decisive criteria for putting fuel cells on the path toward mass series production," Leohold said. "We believe that the high-temperature fuel cell is part of the future. In contrast, we no longer give much chance to low-temperature fuel cells going into series production."

Volkswagen's HTFC cells have new, thinner membranes and electrodes that conceal the complex process of extracting electrical energy from chemical energy to power the electrical engine of future fuel-cell cars.

Low-temperature fuel cells operate at a temperature of approximately 80 degrees Celsius, or about 176 degrees Fahrenheit, but if the energy conversion process gets too hot, the fuel cells can overheat and become damaged.

"This is why vehicle prototypes with LT fuel cells have an extremely sophisticated and expensive cooling system," Volkswagen said.

Instead, the high-temperature membrane developed by Volkswagen can handle temperatures of as much as 120 degrees Celsius, or about 248 Fahrenheit, using phosphoric acid and a much smaller cooling system.

To prevent water from the cooling system from washing the phosphoric acid away, the Volkswagen Technology Center in Isenbuettel coated several pieces of cloth made from carbon fiber with paste that can block the water at the membrane and leave the cells untouched.