Investigation of the Dissolution of CaCrO sub 4 in Molten LiCl-KCl Eutectic

摘要

The rate of dissolution of CaCrO sub 4 in molten LiCl-KCl eutectic was measured by laser Raman spectroscopy after attempts at direct sampling of the melt and cyclic voltammetry proved unsuccessful. Increasing the calcining temperature of the CaCrO sub 4 prepared by General Electric Co., Neutron Devices Dept. (GENDD), for use in Ca/CaCrO sub 4 /Fe thermal batteries resulted in an increase in the average particle size, with a concomitant reduction in the rate of dissolution in the molten eutectic. CaCrO sub 4 obtained from a commercial supplier was found to contain a component that was resistant to dissolution in the molten eutectic; this resistance caused the commercial product to be less reactive than the GENDD-prepared CaCrO sub 4 in Ca/CaCrO sub 4 /Fe thermal batteries. Catholyte mixes formulated with characterized CaCrO sub 4 samples were tested in batteries under various load conditions. The performance of batteries containing the finely divided GENDD CaCrO sub 4 was inferior under light-load conditions to that of batteries with coarser material. The poor performance was the result of enhanced dissolution kinetics of the finer CaCrO sub 4 , which caused greater generation of heat from chemical reactions at the anode. (ERA citation 09:040239)