SELENIUM PRELOADED CATHODE FOR ALKALI METAL-SELENIUM SECONDARY BATTERY AND PRODUCTION PROCESS

A method of producing a pre-selenized (selenium-preloaded) active cathode layer for a rechargeable alkali metal-selenium cell; the method comprising: (a) Preparing an integral layer of porous graphitic structure having a specific surface area greater than 100 m/g; (b) Preparing an electrolyte comprising a solvent and a selenium 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 selenium particles or coating on the graphene surfaces. The selenium particles or coating have a thickness or diameter smaller than 20 nm (preferably