Solid-state lithium ion electrolytes of lithium metal sulfide based composites are provided which contain an anionic framework capable of conducting lithium ions. An activation energy of the lithium metal sulfide composites is from 0.2 to 0.45 eV and conductivities are from 10−4 to 3.0 mS/cm at 300K. Composites of specific formulae are provided and methods to alter the composite materials with inclusion of aliovalent ions shown. Lithium batteries containing the composite lithium ion electrolytes are also provided. Electrodes containing the lithium metal sulfide based composites and batteries with such electrodes are also provided.