Local Structure Analysis of Sulfide-Based Crystallized Glass Solid Electrolytes by Neutron Total Scattering

Solid electrolytes that conduct Na and Li ions are expected to be used in safe and durable all-solid-state batteries. It is known that the ionic conductivity of glass–ceramics, which are formed by crystallization of glass with disorderly arranged atoms by heat treatment, changes from that of the glass before heat treatment and that the disordered atomic arrangement in the crystal dominates the physical properties. Neutron total scattering measurements and reverse Monte Carlo modeling are effective in revealing this local structure. Since Na3PS4 glass–ceramics yields ionic conductivities exceeding 10–4 S cm–1 at room temperature depending on the heat treatment conditions, we investigated the structural factors. The locations of vacancies introduced during the crystal growth process in place of Na, which are speculated to promote Na ionic conduction in Na3PS4 glass ceramics, were revealed.