Phase relationships in positive electrodes of high-temperature lithium aluminum/iron sulfide cells

The phases present in FeS and FeS/sub 2/ positive electrodes of lithium aluminum/iron sulfide cells were determined by x-ray diffraction and by metallographic examinations. The phases found in FeS electrodes were FeS, J(=LiK/sub 6/Fe/sub 24/S/sub 26/Cl), Li/sub 2/FeS/sub 2/, Li/sub 2/S, and Fe. The phases found in FeS/sub 2/ electrodes were FeS/sub 2/, KFeS/sub 2/, Li/sub 3/Fe/sub 2/S/sub 4/, Y phase (approx. Li/sub 7/Fe/sub 2/S/sub 6/), Fe/sub 1-x/S, J, Li/sub 2/S, and Fe. In the absence of potassium-containing phases, the electrode phases are in accord with the Li-Fe-S phase diagram.