Additive for iron disulfide cathodes used in thermal batteries
AssigneeThe United States of America as represented by the United States Department of Energy
InventorsJames R. Armijo, Jimmie Q. Searcy
Life of this patent
Estimating the term…
Abstract
The invention comprises thermal batteries employing an FeS.sub.2 depolarizer, i.e. cathode material, and the depolarizer itself. A minor amount of CaSi.sub.2 preferably, 1-3% by weight is provided as an additive in the FeS.sub.2 depolarizer to eliminate the voltage transient (spike) which normally occurs upon activation of batteries of this type. The amount of FeS.sub.2 by weight generally comprises 64-90%.
Claims12
In a depolarized thermal battery having a plurality of single cell pellets arranged in a stack, with each single cell comprising a heat pellet and, two current collectors having an anode pellet, a separator pellet, and a cathode pellet comprised of FeS.sub.2 and a solid electrolyte, sandwiched therebetween, said thermal battery further including means for activating the battery by melting the electrolyte, the improvement wherein the depolarizer comprises an amount of particulate CaSi.sub.2 effective to substantially eliminate the occurrence of a voltage spike during the initial period of activation of the depolarized thermal battery.
In an FeS.sub.2 depolarizer useful in an LiSi/FeS.sub.2 thermal battery of the type having a solid electrolyte and which is activated by heating and melting of the electrolyte, the improvement wherein the depolarizer contains an effective amount of CaSi.sub.2 whereby when said improved FeS.sub.2 depolarizer is used in said thermal battery the initial voltage transient occurring upon activation is substantially eliminated.
Dependencies are inferred from the claim text.