Conductivity of Alkali Carbonates, Carbonate-Based Composite Electrolytes and IT-SOFC

All facts about the transport properties of molten and solid alkali carbonates, general concepts of solid-state diffusion theory and the analogy in the behavior of liquid and solid ionic salts in terms of ionic transport demand to change the currently dominating view about the nature of the conduction process in molten alkali carbonates. A molten alkali carbonate is a cationic rather than an oxy-anionic conductor, with which the principle of functioning of the conventional molten carbonate fuel cell is wholly compatible. Moreover, the data on the electrical conductivity of alkali carbonate melts reveal that all composite electrolytes comprising a dispersed liquid carbonate and a solid ion conductor matrix do not distinguish themselves by conductivity enhancement. Not only is the phenomenon of superionic conduction in these composites an unparalleled example of scientific fallacy, the principle of functioning of the new IT-SOFC based on the supposed phenomenon is it, too.