Five Types Of Fuel Cells

The first five types of fuel cells are characterised by their low/medium operating temperatures (50-2100C) and their relatively lower energy efficiencies. The other three types of fuel cells are characterised by their high operating temperatures (600-10000C) and their relatively higher energy efficiencies. These fuel cells are capable of directly utilising methane and thus, they possess inherently high efficiencies [16].
Fuel cells provide high reliability and require low maintenance. Due to their silent operation and modular nature, fuel cells are especially suited for localised power generation free from distribution networks. They also find use in uninterrupted power supplies and remote applications. As compared to batteries, fuel cells

SOFCs offer great flexibility in the choice of fuel and are most suited for applications in the stationary power market due to their high conversion efficiencies. These fuel cells can practically operate on hydrocarbon fuels directly and show greater tolerance to impurities in the fuel and to variations in the fuel composition, thereby lowering the fuel processing requirements. The high operating temperature of SOFCs leads to the production of high-quality heat as a by-product, which can be further used in CHP systems, or to drive a gas turbine to produce more electricity. The solid-state construction of SOFCs ensures that there are no moving parts. This leads to less wear and tear, and largely silent operation. Moreover, the absence of a liquid electrolyte rules out potential problems due to corrosion and loss of electrolyte. SOFCs do not contain any noble or precious metals and hence, are much cheaper to fabricate on a large scale. Lastly, these fuel cells have extremely low emissions of gaseous pollutants and have a potential life expectancy of 40000-80000 hours [16,

The cathode material must be stable in an oxidising environment and the porous microstructure must be maintained at the high temperatures of operation. Noble metals and electronically conducting oxides are thus the ideal choices for cathode materials for SOFCs. However, the use of noble metals is not practically feasible due to their high cost and hence, electronically conducting oxides are generally used. The thermal expansion coefficient of these oxides and that of the solid electrolyte must be very similar and the cathode materials must be chemically compatible with the solid electrolyte [17]. Perovskite-based LaMnO3 is the most commonly used cathode material for SOFCs. Strontium is usually doped with LaMnO3 to form strontium-doped lanthanum manganite (LSM), which exhibits increased electronic conductivity