NEW LITHIUM SOLID ELECTROLYTES, THIO-LISICON: MATERIALS DESIGN CONCEPT AND APPLICATION TO SOLID STATE BATTERY

摘要

Materials design concept of the new crystalline 'thio-LISICON' (Lithium Superlonic CONductor) family was discussed. The thio-LISICON was found in the ternary systems, Li_2S-MS_2-M'_xS_y (M=Si, Ge, M' -P, Sb, Al, Zn, etc), and showed the highest conductivity of 2.2 x 10~(-3) Scm~(-1) at 25℃ of any sintered ceramic, together with negligible electronic conductivity, high electrochemical stability, no reaction with lithium metal, and no phase transition up to 300℃. The advantage and disadvantage of the crystalline materials were discussed based on the ionic conduction, chemical stability and electrochemical potential window.