ABSTRACT
The polymer electrolyte membrane fuel cell (PEMFC) was first developed by General Electric in the United States during the 1960s, for use by NASA on their first manned space vehicles. This type of fuel cell depends primarily on a special polymer membrane that is coated with highly dispersed catalyst particles. The bipolar plates that form a significant part of the weight and volume of a PEMFC are used to bring the reactant gases via machined flow channels to the membrane electrode assembly. The reaction in a single fuel cell produces an output voltage of around 0.7 V; for general applications, several individual cells are connected in series to form a fuel cell stack to produce the desired voltage additively. A practical fuel cell stack may get the hydrogen fuel from a pressurized tank through regulated valves, or the hydrogen is obtained indirectly from a hydrogen-rich fuel like natural gas via a fuel processor called the reformer.
