US Patent 7510808 Low temperature Li/FeS

The invention is a 1.5 volt primary electrochemical battery cell with an alkali metal lithium negative electrode (such as lithium), a positive electrode (comprising iron disulfide for example) and a nonaqueous electrolyte. The electrolyte has a solute including lithium iodide dissolved in an ether-containing solvent including a 1,2-dimethoxypropane based solvent component and no more than 30 volume percent 1,2-dimethoxyethane. When 1,2-dimethoxypropane is used to replace at least most 1,2-dimethoxyethane in the solvent, the cell provides good discharge capacity at low temperature while maintaining excellent discharge capacity at room temperature.