A study of electrolyte melts for use in fused salt fuel cells.

摘要

A molten salt electrolyte with an oxygen ion conductor for use in fuel cell developed starting from the simplest alkali-halide system.;The constraints which had to be met by the proposed electrolyte system were: (1) Intermediate operating temperature. between that of current fuel cell systems, 250 to 450°C. (2) Halide melt should be stable in the presence of oxidizing and reducing gases. (3) Incorporate an oxygen ion conductor into the alkali-halide melt capable of regeneration from oxygen cathode gas (air) and the reducing anode gas and possess high ionic conductivity.;A systematic approach was used beginning with thermodynamic paper studies, verified from thermal analysis, to select potentially stable systems. Once this was achieved, the halide melt was further discriminated by choosing the system with the highest conductivity between 250°C and 450°C. Then, an oxygen ion conductor was added to the halide in the form of a multi-valent oxide.;The final electrolyte system consisted of a LiCl-KCl eutectic mixture with 5 mass % V2O5. This electrolyte was found to exhibit a single phase melt at 400°C and conductivity superior to that of the Alkaline Fuel Cell (5N KOH, 23°C) and the Molten Carbonate Fuel Cell (62 mole % Li2CO3 - 38 mole % K2CO3 , 650°C).;It is perceived that this system will provide improved power generating properties, over current fuel cell systems, due to its more favorable polarization characteristics. The merits of this electrolyte system will only be fully realized when a proper fuel cell unit is examined.