Imagine going for days or even weeks at a time without recharging your laptop or cell phone. Using a new fuel-cell design that circumvents the technology's limitations, researchers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., may make this kind of longevity a reality.
Current fuel cells are too large for use in portable electronics. Operating at high temperatures, they require bulky thermal insulation. Much of their weight and size also derives from the bipolar plates needed to connect several cells to form a stack. But JPL has eliminated the bipolar plates and created a monopolar pack, which is flat with cells linked by electrical interconnects.
Compact and flat, the cell resembles a pair of paperback books standing back to back (see the figure). It weighs substantially less than previous cells. This 5-W portable power unit also can be refueled instantly with liquid methanol to extend operation time as needed without interruption. The methanol is put in one side of the unit while air circulates on the other side. Both are circulated past electrodes and converted to electricity.
The next step is to make it much smaller and more robust and user-friendly. Someday, the researchers hope, similar fuel cells will replace batteries in portable electronics. For details, go to www.jpl.nasa.gov.