ELECTROCHEMICAL BEHAVIORS OF LI+ ION CONDUCTOR, LI3PO4-LI2S-SIS2

There are great interests on sulfide glasses because of their high lithium ion conductivity. We synthesized a new lithium ion conductive solid electrolyte, Li3PO4-Li2S-SiS2 to obtain a solid electrolyte with high ionic conductivity and electrochemical stability. Its conductivity at room temperature was 7.6 x 10(-4) S/cm, and proved to be stable against electrochemical reduction. We also investigated the electrochemical behaviors of spherical graphite with this electrolyte as a preliminary study for solid-state batteries and proved that spherical graphite seems a good candidate for negative electrode material in the solid-state batteries.