Abstract: Described herein are various embodiments of methods of making an all-solid-state electrode material for a rechargeable battery comprising in a first mixing step, mixing one of a transition metal phosphide, a transition metal oxide, and a transition metal sulfide with sulfur to produce a first mixture, in a first heat-treating step, heating the first mixture to a temperature ranging between about 250 degrees C. and about 450 degrees C. to produce a heat-treated second mixture comprising an active material and a glass former/electrolyte precursor, in a second mixing step, mixing the second mixture with a glass/electrolyte modifier to produce a third mixture, and permitting the third mixture to react to produce the cathode material, the cathode material comprising the active material and a solid state electrolyte. Electrode materials, electrodes, and batteries made using the foregoing and similar methods are also described.