Cool Fuel Cells

Fuel cells promise to be the environmentally-friendly power source of the future, but some types run too hot to be practical. New research may have a solution.

Astronauts have been using them for power aboard spacecraft since the 1960s. Soon, perhaps, they'll be just as common on Earth - powering cars, trucks, laptop computers and cell phones.

They're called fuel cells.

By combining hydrogen fuel with oxygen, fuel cells can produce plenty of electric power while emitting only pure water as exhaust. They're so clean that astronauts actually drink the water produced by fuel cells on the space shuttle.

In recent years the interest in bringing this environmentally friendly technology to market has become intense. But there are problems: You can't "fill 'er up" with hydrogen at most corner gas stations. And fuel cell-based cars and computers are still relatively expensive. These obstacles have relegated fuel cells to a small number of demo vehicles and some specialty uses, such as power aboard the space shuttle and back-up power for hospitals and airports.

Copyright Toyota Motors more The Toyota FINE-S, a hydrogen fuel-cell hybrid-electric concept vehicle revealed at the North American International Auto Show in January 2003.

Now new research is helping to tackle some of these obstacles. By finding a way to build "solid oxide" fuel cells that operate at half the temperature of current designs - 500°C instead of a blistering 1,000°C - researchers at the Texas Centre for Superconductivity and Advanced Materials (TcSAM) at the University of Houston hope to make this kind of fuel cell both cheaper to manufacture and easier to fuel.

"Our key advance was making the heart of the fuel cell - the sheet of electrolyte that controls the flow of electrically charged ions - out of a thin film only one micron thick," says Alex Ignatiev, the director of TcSAM.

In contrast, today's off-the-shelf solid-oxide fuel cells have electrolyte layers 100 microns thick or more (a micron is one thousandth of a millimetre). Ignatiev explains: "The thinness cuts down internal resistance to electric current, so we can get comparable power output at much lower operating temperatures."