The development of modern fuel cells has been driven by the need to generate clean and efficient electrical power for different applications. The first demon­stration of a fuel cell was described by William Grove in 1839. Grove was inspired by the observation that electrolysis of water produces hydrogen and oxygen gas. He ran the process in reverse by feeding oxygen to a Pt cathode and hydrogen to a Pt anode, where all electrodes were immersed in a common sulfuric acid bath. Several such cells were connected in series to generate voltage that was measured as shown in Figure 9.2. This “gas voltaic battery” was of little practical value.

Notable work done in the late 19th century by Ludwig Mond and Charles Langer aimed to produce a working fuel cell run on air and industrial coal gas. They were the first to suggest the use of “stacks” of cells with manifolds to deliver fuel and oxidant streams. William White Jaques, who is generally credited with coining the term “fuel cell,” replaced Grove’s sulfuric acid electrolyte with a phosphoric acid electrolyte. All of these systems fell short of producing practical power plants.

Francis T. Bacon, direct descendant of the renowned and similarly named philosopher, was first in developing a truly useful fuel cell power plant in 1959. It was a 5-kW system used to power a welding machine. It used nickel electrodes and an alkaline KOH electrolyte. Later that same year, Harry Karl Ihrig demon­strated the first fuel cell-powered vehicle, an Allis Chalmers tractor, powered by 1008 cells split into 112 stacks comprising a 15-kW power source [1,2,3]. Bacon’s fuel cell design was the product of more than a quarter century of effort on his part and was the basis for rapid development of fuel cells during the “space race” between the United States and the Soviet Union. Fuel cell development culmi­nated in the use of fuel cells in the Gemini and Apollo missions during the late 1960s and early 1970s [1,2,3]. It is interesting to note that during the earlier Mercury missions and Gemini missions 1 through 4, batteries were used for power. In Gemini 5 and later missions, power was generated by polymer elec­trolyte fuel cells (PEFCs). In the Apollo missions, PEFCs were replaced by the alkaline fuel cell design because of performance problems caused by oxygen crossover and PEM instability.

The early 1970s to the present can arguably be thought of as the modern era of fuel cell development. A modern fuel cell design generally falls into one of five categories: alkaline fuel cell (AFC), polymer electrolyte fuel cell (PEFC), phosphoric acid fuel cell (PAFC), molten carbonate fuel cell (MCFC), and solid oxide fuel cell (SOFC). All of the categories generate considerable attention in the scientific and patent literature.

Evolution of the modern DMFC is intimately linked to the development of the modern low-temperature PEFC. PEFCs fueled with a pure hydrogen or refor­mate stream have received the majority of attention in the literature as the top candidate for power systems ranging from the 10-3 to 105 W needed for power plants. The recent historical development of the PEFC follows a bifurcated path of parallel development of electrocatalysts and PEMs. DMFCs are under increas­ing consideration as an attractive alternative to PEFCs because of the inherent economic and technological limitations of hydrogen production and storage [1,2,3,4,5].