NEW IRON SULFUR CATHODES FOR NON-AQUEOUS LITHIUM BATTERIES

The compounds KFeS2 and M0.5FeS2 (M = Sr, Ba) are shown to behave as electrochemically active, reversible cathode materials in nonaqueous lithium electrochemical cells. The compounds are characterized by infinite chains of edge-shared tetrahedra supported by the alkali or alkaline earth metal. All the iron is in the 3+ oxidation state. Cell data and reactions with n-butyl lithium show that one lithium per iron may be incorporated with a structural rearrangement and reduction of Fe3+ to Fe2+. © 1979, The Electrochemical Society, Inc. All rights reserved.