Classification of Fuel Cells

In the 1960s and 1970s, three distinct fuels cells were designed, developed, and evaluated mostly by scientists and engineers in the United States and European countries. But their performance parameters, such as current densities, terminal voltages, and continuous operating hours, were marginal. Early developed fuel cells can be briefly described as follows. 

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Table 3.2 Classification of fuel cells and their main characteristics...

The most common classification of fuel cells is by the type of electrolyte used as shown in Table 1 which summarizes the most commonly used fuel cell technologies and their applications. The operating temperature and useful life of a fuel cell dictate the physicochemical and thermomechanical properties of materials used in the cell components (i.e., electrodes, electrolyte, intercoimect, cm-rent collector, etc.)... 

Principles, Functions, and Classification of Fuel Cells 435 Tab. 2 Operating parameters of different types of fuel cells... 

General Aspects and Classification of Fuel Cell Systems. Despite their... 

Fuel cells are electrochemical devices that convert chemical energy contained in fuel directly into electrical energy through electrochemical reactions. Fuel cells consist of an anode, where the fuel is oxidized, a cathode where the oxidant is reduced and an electrolyte which separates anode from cathode and conducts ions. The general classification of fuel cells is usually based on the type of electrolyte used, and their operation conditions are typically related to the characteristics of the electrolyte. More detailed discussion of fuel cells as stand-alone power sources can be found in the next chapter of this book. 

Table 3.2. Classification of fuel cells on the basis of temperature...

Classification of fuel cells by temperature is becoming more blurred, however, since a current SOFC research focus is lower temperature (<600°C) operation to improve start-up time, cost and durability, while a focus of PEFC research has been to increase operation temperature to > 120°C to improve waste heat rejection and water management. The ideal temperature seems to be around 150-200°C which is where the PAFC typically operates. However, the PAFC has its own historical limitations which have hampered enthusiasm for its continued development. 

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