Electrochemical battery cells, and more particularly, to cells comprising a lithium negative electrode and an iron disulfide positive electrode. Before use in the cell, the iron disulfide has an inherent pH, or a mixture of iron disulfide and an pH raising additive compound have a calculated pH, of at least a predetermined minimum pH value. In a preferred embodiment, the pH raising additive compound comprises a Group IIA element of the Periodic Table of the Elements, or an acid scavenger or pH control agent such as an organic amine, cycloaliphatic epoxy, amino alcohol or overbased calcium sulfonate. In one embodiment, the iron disulfide particles utilized in the cell have a specific reduced average particle size range. Methods for preparing cathodes and electrochemical battery cells comprising such cathodes including (a) iron disulfide or (b) a mixture of iron disulfide and the pH raising additive compound, having (a) an inherent pH or (b) a calculated pH greater than or equal to a predetermined minimum value are disclosed.