Down the Line: Portable Fuel Cells
"This is a significant advance in fuel cell development because by going small, you make the fuel cell portable and viable for use as a power source to operate small appliances that require long operating time, such as laptops," says Dr. Sekharipuram Narayanan, JPL’s fuel cell technical team leader. "Instead of recharging your laptop every 2 hours, imagine being able to use it for 10 hours at a time."
Existing fuel cells typically operate at high temperatures, require bulky thermal insulation and use hydrogen as their energy source. Much of their weight and size is due to the bipolar plates needed to connect several cells to form a stack. Narayanan and his colleagues have eliminated bipolar plates and created a "monopolar pack," which is flat with the cells linked by electrical interconnects.
A fuel cell works on the same principle as a battery, but is continually fed with fuel. For instance, in JPL’s new power source, methanol is put in on one side of the unit while air circulates on the other side. Both are circulated past electrodes and converted to electricity. The process produces no toxic emissionsonly carbon dioxide and water as byproducts.
A major advantage of fuel cells over rechargeable batteries is that they can operate for longer periods of time without recharging or interruption. Unlike batteries, fuel cells can be recharged almost instantaneously by refueling with liquid methanol.