Recent Developments in Li(Si)/FeS sub 2 Thermal Battery Technology

摘要

The Li(Si)/FeS sub 2 electrochemical system has been under development for thermal battery applications as an alternative to Ca/CaCrO sub 4 for several years at Sandia National Laboratories (SNL). The new technology differs from the old in that the anode is a pressed powder (44 wt % lithium in Li(Si) alloy) as opposed to sheet calcium or bimetal; and a separator composed of LiCl.KCl eutectic electrolyte and MgO binder is required with a separate cathode pellet composed of FeS sub 2 and electrolyte to replace the DEB pellet; and current collectors which may actually function as temperature moderators are always used. The applications require high reliability (typically, a success probability of 0.995) and a twenty-five year shelf-life. Consequently, a substantial materials effort has been necessary to assess degradation and deleterious reactions during storage and to determine necessary production specifications and controls. Experience with several applications has indicated that Li(Si)/FeS sub 2 thermal batteries are easier to develop and produce than those which use Ca/CaCrO sub 4 . Furthermore, the new system is more capable and more forgiving. Therefore, an effort has been initiated to develop the new technology for all SNL thermal battery applications. This paper reviews both the materials-related development and the progress toward utilization of Li(Si)/FeS sub 2 for all SNL thermal battery applications. (ERA citation 07:054095)