SUPERIORITY OF LI2CO3 NA2CO3 ELECTROLYTE IN MOLTEN-CARBONATE FUEL-CELLS .1. INFLUENCE OF OPERATION CONDITIONS ON POLARIZATION BEHAVIOR/

Molten Li/Na carbonate (53/47 mole ratio) has hardly been used as the electrolyte of molten carbonate fuel cells because of the high polariz ation under an pressure. The Li/Na carbonate cell, however, has a poss ibility of high because of its high ionic conductivity. In order to ta ke advantage of this characteristic, we conducted thorough examination s on the Li/Na carbonate cell performances in the wide range of operat ing conditions which include high pressure conditions, in comparison w ith the Li/K carbonate cells. It turned out that the Li/Na carbonate c ell has lower performance than Li/K carbonate cell at low Po-2 in the oxidant gas, while the Li/Na carbonate cell has higher performance at high Po-2. Moreover the pressure gains of the cell voltage are also hi gher (Delta V=120 mV/decade) than that of the Li/K carbonate cell beca use the cathode polarization of the Li/Na carbonate cell has higher pr essure dependence than that of the Li/K carbonate cell. The superiorit y of the Li/Na carbonate cell at high pressure operation is demonstrat ed.