ALKALI METAL-SULFUR SECONDARY BATTERY CONTAINING A PRE-SULFURIZED CATHODE AND PRODUCTION PROCESS

A method of producing a pre-sulfurized active cathode layer for a rechargeable alkali metal-sulfur cell; the method comprising: (a) preparing an integral layer of mesoporous structure of a carbon, graphite, metal, or conductive polymer having a specific surface area greater than 100 m/g; (b) preparing an electrolyte comprising a solvent and a sulfur source; (c) preparing an anode; and (d) bringing the integral layer and the anode in ionic contact with the electrolyte and imposing an electric current between the anode and the integral layer (serving as a cathode) to electrochemically deposit nanoscaled sulfur particles or coating on the graphene surfaces. The sulfur particles or coating have a thickness or diameter smaller than 20 nm (preferably