Synthesis and electrochemical performance of sulfur-carbon composite cathode for lithium-sulfur batteries

摘要

In this paper, porous carbon was synthesized by an activation method, with phenolic resin as carbon source and nanometer calcium carbonate as activating agent. Sulfur-porous carbon composite material was prepared by thermally treating a mixture of sublimed sulfur and porous carbon. Morphology and electrochemical performance of the carbon and sulfur-carbon composite cathode were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectra (EIS), and galvanostatic charge-discharge test. The composite containing 39 wt.% sulfur obtained an initial discharge capacity of about 1,130 mA h g~(-1) under the current density of 80 mA g~(-1) and presented a long electrochemical stability up to 100 cycles.