Taking on the Energizer Bunny; April 1998; Scientific American Magazine; by Hayashi; 1 Page(s)
Batteries are a notorious weak link for many portable devices, such as laptop computers and cellular phones. They are expensive, heavy and cumbersome, often requiring recharging at the most inopportune times. Recent advances in fuel-cell technology might bring relief. Several research groups are developing "micro-fuel cells" that could, for example, result in mobile phones running continuously for weeks on standby power.
Fuel cells are simple devices, basically consisting of a nonmetallic conductor called an electrolyte sandwiched between two electrodes. Hydrogen from a fuel, such as methanol, flows through the electrolyte to mix with an oxidizer, such as oxygen from air, and the chemical reaction produces an electric current between the two electrodes. The cells can be replenished easily--and quickly-- by adding more fuel. Fuel cells also run cleanly, their main by-product being water from the combination of hydrogen and oxygen, whereas batteries, which eventually wear out from repeated recharging, present a disposal problem.