PROCESS FOR PRODUCING LITHIUM IRON SULFIDE, AND PROCESS FOR PRODUCING LITHIUM TRANSITION METAL SULFIDE

摘要

A process for producing lithium iron sulfide, which is characterized by comprising: a first step of mixing an iron sulfide (a) with sulfur to produce a mixture of the iron sulfide (a) and sulfur, and subsequently burning the mixture of the iron sulfide (a) and sulfur in an inert gas atmosphere to produce an iron sulfide (b) that has an almost single phase as determined by an X-ray diffraction analysis and has a molar ratio of the content of element iron to the content of element sulfur (i.e., an Fe/S ratio) of not less than 0.90 and less than 1.00; and a second step of mixing the iron sulfide (b) with lithium sulfide to produce a mixture of the iron sulfide (b) and lithium sulfide, and subsequently burning the mixture of the iron sulfide (b) and lithium sulfide in an inert gas atmosphere to produce lithium iron sulfide represented by formula Li2FeS2.