U.S. Department of Energy - Energy Efficiency and Renewable
Energy Fuel Cell Technologies Office – Fuel Cells Parts of a
Fuel Cell Polymer electrolyte membrane (PEM) fuel cells are the
current focus of research for fuel cell vehicle applications.
PEM fuel cells are made from several layers of different
materials, as shown in the diagram. The three key layers in a
PEM fuel cell include: Other layers of materials are designed to
help draw fuel and air into the cell and to conduct electrical
current through the cell. Membrane Electrode Assembly The
electrodes (anode and cathode), catalyst, and polymer
electrolyte membrane together form the membrane electrode
assembly (MEA) of a PEM fuel cell. Anode. The anode, the
negative side of the fuel cell, has several jobs. It conducts
the electrons that are freed from the hydrogen molecules so they
can be used in an external circuit. Channels etched into the
anode disperse the hydrogen gas equally over the surface of the
catalyst. Cathode. The cathode, the positive side o