Nickel-Layer protected, carbon-coated sulfur electrode for lithium battery.

In this work we propose a new approach to make the sulfur electrode a valid candidate cathode for high energy lithium batteries. We report the synthesis and characterization of a nickel-layer protected carbon-coated sulfur as positive electrode for lithium battery [1]. The electrode is prepared by annealing sulfur and pitch in argon atmosphere followed by mechanical treatment and covered by a thin layer of nickel metal by using laser beam assisted vapor deposition (LBVD). We synthetized three materials : the first material is obtained by annealing sulfur and pitch ; this sample ( named S1) then is treated with Super P carbon, by planetary milling system (Spex mill) with agate sample holder and spheres, to obtain the sample S2. Finally S2 is plated as electrode on aluminum support and covered by thin film of nickel metal (named as S3).The structure and the morphology of the electrode are first characterized by scannig electron microscopy (SEM) and by X ray diffraction (XRD), while the electrochemical characteristics are studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic cycling in lithium cells. The results demonstrated that the synthesis procedure greatly enhances the S-C cathode electrochemical properties in both terms of reaction Kinetic and capacity retention. These improvements are attributed to increasing of the electrode conductivity and to the reduction of the polysulfides dissolution.