ARTICLE

July 2003

Fuel Cells Could Help Army Cut Back on Batteries

by Sandra I. Erwin

The Army today employs 300 different types of batteries to power every imaginable device—ranging from riflescopes to radios and missile launchers.

A battalion preparing for war literally must bring tens of thousands of batteries to the battlefield, creating enormous logistical burdens.

The battery problem is of particular concern for dismounted soldiers, who already carry more than 100 pounds of gear and cannot afford to be weighed down with additional battery packs.

“Getting the soldier load down and having power sources that will power all the devices the soldier uses is a significant challenge,” said George Fisher, an Army advisor at the Oak Ridge National Laboratory. “We need some breakthroughs in that area.”

Experts say the Army’s best hope for an alternative source of “soldier power” is in miniature fuel-cell technology.

One of many ongoing efforts in this arena is under way at the Department of Energy’s Pacific Northwest National Laboratory. Under sponsorship of the Defense Advanced Research Projects Agency, the lab is developing miniaturized low-watt power sources that could be used in soldier devices such as sensors and hand-held wireless systems.

About the size of a cigarette lighter, these tiny power systems convert liquid fuel to electricity via a micro-scale fuel processor coupled with a micro-scale fuel cell. PNNL’s fuel reformer, the size of a pencil eraser, converts fuel and water into hydrogen-rich gas. The fuel cell then generates electricity by converting hydrogen and oxygen from the air into electrical power and clean water.

Tests have shown that the system can produce an equivalent power to batteries at about one-third the weight, said Evan Jones, a PNNL researcher.

Battery performance may improve in the future, but only “incrementally,” said Jones. In the long term, the Army will need to rely on fuel cells if it wants lighter and more efficient power sources, he said. “To get orders of magnitude improvement, you need liquid fuel.”

In principle, fuel cells will generate electricity for as long as the fuel—generally hydrogen gas—is supplied. However, providing hydrogen in small quantities for compact equipment can be a drawback.

The technology so far only has been tested in the lab and will not be ready for field tests until 2006, said Jones. It is not yet certain that these fuels cells will be rugged enough to survive in harsh environments or combat conditions.

If the project proves successful, a long-term goal is to be able to power the fuel cells with reformed JP-8, the Army’s standard fuel.

“As long as we have JP-8, how do we turn it into hydrogen to get it into the fuel cell?” asked John Pellegrino, an Army scientist.

He said that the fuel-reforming technology is “not there yet. ... You need a reformer plant of pretty substantial size to get rid of the sulfur [in the JP-8 fuel].” One way to counter that problem would be to develop sulfur tolerant catalysts and fuel cell electric-catalyst membranes that can be used with a higher degree of sulfur, Pellegrino said.

The Army’s expressed desire to do away with batteries in favor of fuel cells increasingly is driving private investments in this technology.

A case in point is a partnership signed six months ago between Harris Corporation—a supplier of military radios—and MTI MicroFuel Cells Inc.

The companies agreed to fund the development of micro fuel cell prototypes for potential use in tactical radios.

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