Sulfide Glass-Ceramic Electrolytes for All-Solid-State Lithium and Sodium Batteries

Sulfide glass-ceramic electrolytes with Li+ or Na+ ion conduction have been developed in last decade. High-temperature phases of Li7P3S11 and cubic Na3PS4 are precipitated from mother glasses, and the obtained glass-ceramics show higher conductivity than the mother glasses. It is difficult to synthesize those high-temperature phases by conventional solid-state reaction, and glass electrolytes are thus important as a precursor for forming high-temperature phases. The highest conductivities at 25 degrees C of 1.1x10(-2)S/cm for Li+ ion conductor (Li7P3S11) and 7.4x10(-4)S/cm for Na+ ion conductor (Na3.06P0.94Si0.06S4) are achieved in sulfide glass-ceramic electrolytes. All-solid-state batteries with sulfide glass-ceramic electrolytes were fabricated by cold press at room temperature. Sulfide electrolytes have favorable mechanical properties to form favorable solid-solid contacts in solid-state batteries by pressing without heat treatment. All-solid-state Li-In/S and Na-Sn/TiS2 cells using sulfide glass-ceramic electrolytes operate as secondary batteries and exhibit good cycle performance at room temperature.