BEHAVIOR OF TITANIUM SPECIES IN MOLTEN LI2CO3-NA2CO3 AND LI2CO3-K2CO3UNDER ANODIC AND CATHODIC CONDITIONS - I - THERMODYNAMIC PREDICTIONS AT 550-750-DEGREES-C

The electrochemical stability domains of Li2CO3-Na2CO3 and Li2CO3-K2CO 3 are established at different temperatures in the anodic and cathodic conditions generally used in the molten carbonate fuel cell, on the b asis of thermochemical calculations. Thermodynamic predictions on the stability of titanium species, according to the nature of the carbonat e melt and the acidity level, are systematically developed under both oxidizing (O-2:CO2) and reducing (H-2:CO2:H2O:CO) atmospheres. In all the cases Ti (IV), in an Li2TiO3 form, is the stable species all over the acidity range. A partial transformation of this lithiated compound into other solid or liquid forms is also fully investigated. (C) 1998 Elsevier Science Ltd. All rights reserved.