Electrochemical properties of graphite were investigated using SiS2-based glass or P2S5-based glass as a solid electrolyte. Graphite showed reversible electrode reactions in the P2S5-based glass, while it did not in the SiS2-based one. The results of X-ray diffractometry and Raman spectroscopy indicated that the SiS2-based glass was reduced as side reactions instead of the intercalation of lithium ions into graphite during the reduction, resulting in the poor reversibility. (C) 2003 The Electrochemical Society.