On the Path to Practical Solid Oxide Fuel Cells

5 On the Path to Practical Solid Oxide Fuel Cells 

By 19 70 the results of investigations on properties and applications of solid oxide electrolytes were so numerous as to make them very difficult to survey. A comprehensive review by Etsell and Flengas included 674 references [126]. But commercial activity was confined to potentiometric oxygen sensors. In the USA, the programme for development of SOFCs ran out in 19 70. The greatest obstacles 

Fuel Electrode-Type Material Over Interconnection is the 0 Contact Surface of Single Cell 

In 1994, new solid electrolytes with high conductivity at low temperatures were found in the form of doped lanthanum gallates [142]. Since the selfdiffusion coefficients of cations are apparently fundamentally larger in the perovskite-type oxides than in fluorite oxides, lanthanum gallate electrolyte and associated electrode materials tend to react too easily at the temperatures of fabrication and operation of cells. 

At low operation temperatures, polarisation losses and the importance of catalysis of the electrode reactions Increase. At the cathode, mixed potentials can arise when traces of combustible substances determine the electrode potential in competition with oxygen, an effect, mentioned near the end of Section 2.3, whose cause was recognised by Hartung in 1981 [143], today the basis of the development of hydrocarbon sensors. For the anodes growing interest is directed to materials which accelerate the electrochemical oxidation of CO and hydrocarbons and is stable against fuel impurities. 

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