Molten iodide-based salts due to their low melting points were envisaged to improve the performances of thermal batteries. Iodide-based salt drying and the determination of the basic properties (electrochemical window, conductivity, thermal heat capacity,...) of some electrolytes were carried out. The results obtained showed that some of iodide-based electrolytes are suitable for thermal batteries. In addition, the LiF-LiCI-LiI and LiF-LiBr-KBr electrolytes were tested in Li-Si/FeS2 single cells in the temperature of thermal battery operating conditions. The LiF-LiCI-LiI electrolyte could be considered as an interesting alternative for the improvements of thermal battery performances. (c) 2006 Elsevier B.V All rights reserved.