Lithium electrochemical cells with enhanced cycle life

The present invention generally relates to the field of electrochemical cells. More particularly, the invention pertains to lithium rechargeable cells with long cycle life, preferably cells comprising sulfur-containing cathode materials, and to methods of making these cells. A secondary lithium-sulfur electrochemical cell is provided comprising: (a) an anode comprising lithium; (b) a cathode comprising an electroactive sulfur-containing material; and (c) a non-aqueous electrolyte interposed between the anode and the cathode, wherein the electrolyte comprises: (i) one or more lithium salts; (ii) one or more non-aqueous solvents; and (iii) a cycle life enhancing amount of water; wherein the cycle life enhancing amount of water is greater than 3000 ppm by weight of the electrolyte. Such cells have a long cycle life.