Electrochemical properties of lithium–sulfur batteries

Abstract Lithium–sulfur cells are fabricated in a dry room, and comprise a positive (cathode) active material of sulfur, a negative (anode) active material of lithium metal, and an electrolyte of 1 M LiCF 3 SO 3 dissolved in tetraglyme (TG)/1,3-dioxolane (DIOX). For types of electrolyte with different contents of TG and DIOX are prepared. The electrochemical properties of the batteries are analyzed by scanning electron microscopy, cyclic voltammetry, ac impedance experiments, and charge–discharge tests. The conductivity of the four different electrolytes are investigated. The conductivity of an electrolyte of 1 M LiCF 3 SO 3 dissolved in TG/DIOX (50:50, vol.) is greater than that of the other three types of electrolyte with different volume ratios (70:30, 30:70) and a single solvent (TG). A cell with 1 M LiCF 3 SO 3 dissolved in TG/DIOX (50:50, vol.) gives the best reversibility and cycle performance.