Environmental Engineering Reference
In-Depth Information
Fuel cells can come in different sizes.
player, then back to
the battery again.
The electrons follow
a
circuit
(a loop). The
result? You hear music!
The low of electrons
in and out of a battery
continues as long as the
chemical reaction takes
place and the electrons travel through a device (like the music
player described above) or a wire. There is a limited amount
of chemicals inside the battery, and as the reactions occur, the
chemicals are used up or changed. This is why a battery can
“go dead.” At some point, it runs out of the chemicals that react
with each other. A fuel cell, though, uses a supply of chemicals
that comes from outside the cell. This means that the supply
can be controlled so that the chemicals needed for the reaction
never run out. The chemicals that fuel cells use are hydrogen
and oxygen.
A Typical Fuel Cell
Every fuel cell has two
electrodes
. An electrode is a terminal,
or place, where an electrical current is conducted. An electrode
can have either a positive or a negative charge. The chemical
reactions in a fuel cell take place at the electrodes. The
electrodes are good conductors of electricity.
Every fuel cell also uses some type of
electrolyte
. An
electrolyte is a material that carries electrically charged
