A lithium sulfide (Li2Sw)-lithium phosphorus sulfide (LixPySz) composite, electrochemical cells comprising the same, and methods for making the same are described herein. By the mechanochemical method described herein, the Li2Sw—LixPySz composite can be formed and used as the active material in a positive electrode for a variety of electrochemical cells. It is shown herein that the composite is an electrochemically active cathode material. Further, it has been shown that the Li2Sw—LixPySz composite shows increased resistance to decomposition and H2S generation than Li2S.