Hydrogen, energy conversion polymer electrolyte fuel cell

The conversion of chemical energy to electrical energy in a PEM fuel cell occurs through a direct electrochemical reaction. It takes place silently without combustion. The key part of a PEM fuel cell, which is known as a membrane electrode assembly (MEA), consists of a polymer electrolyte in contact with an anode and a cathode on either side. To limction, die membrane must conduct hydrogen ions (protons) and separate either gas to pass to the other side of the cell. A schematic representation of a PEM fuel cell is shown in Figure 1.5. 

A detailed description of the energy conversion processes through electrochemical reactions in a fuel cell is given here by considering a hydrogen-oxygen polymer electrolyte membrane fuel cell (PEMFC) and a solid oxide fuel cell (SOFC) with basic cell components as shown in Figures 4.6 and 4.7, respectively. Similar descriptions for other types of fuel cells will be presented in Chapter 9. 

---