**2. Functions of bipolar plates**

**Figure 9.** Showing components of molten carbon fuel cell (www.iit.edu)

**1.7. Polymer electrolyte membrane fuel cell: A case study**

The different components of PEMFCs are as follows:

the anode and cathode interface.

serving as its transport medium.

**•** Gas diffusion layers (GDL)

products.

**•** Bipolar plates

240 Electrodeposition of Composite Materials

Polymer electrolyte membrane fuel cell also known as proton exchange membrane fuel cell

The major portion of the fuel comprises hydrogen (H2) and oxygen (O2) from air which together acts as an oxidant. Both react together electrochemically producing electricity and water as by-

**•** "Anode" is the negative electrode that conducts freed electrons to an external circuit.

recombine with the hydrogen ions and the oxygen to form water and heat.

**•** "Cathode" is the positive electrode that distributes oxidant to the surface of the catalyst and it also conducts the electrons back from the external circuit to the catalyst where they can

**•** "Catalyst" usually made up of platinum serves the purpose of splitting fuel and oxidant at

**•** "The electrolyte" is the proton exchange membrane that is only permeable to hydrogen ions

has been proposed to be a suitable candidate for use in fuel cell vehicles[2].

Bipolar plates perform a number of critical functions simultaneously in a fuel cell stack to ensure acceptable levels of power output and a long stack lifetime[14]as described in the following:

