Nickel-Layer Protected, Carbon-Coated Sulfur Electrode for Lithium Battery

In this paper we report the characterization of a nickel-layer protected carbon-coated sulfur as positive electrode for lithium battery. The electrode is prepared by annealing sulfur and pitch-carbon in argon atmosphere followed by mechanical treatment. The electrode is further covered by a thin layer of nickel metal by using electron beam physical vapor deposition (EBPVD). The structure and the morphology of the electrode are first characterized by scanning 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 kinetics and capacity retention. These improvements are attributed to the increasing of the electrode conductivity and to the reduction of the polysulfides dissolution. In this paper we propose a new approach to make the sulfur electrode a valid candidate cathode for high energy density lithium batteries. (C) 2012 The Electrochemical Society. [DOI: 10.1149/ 2.039204jes] All rights reserved.