An All-solid-state Sodium–Sulfur Battery Operating at Room Temperature Using a High-sulfur-content Positive Composite Electrode

The performance of an all-solid-state sodium–sulfur (Na–S) battery at 25 °C, in which the sulfur content in the positive composite electrode was 50 wt % to enhance energy density, was investigated. All-solid-state Na–S cells prepared using a positive composite electrode with a high-phosphorus-to-sulfur-ratio solid electrolyte exhibited a high capacity of approximately 1500 mA h g−1 at 0.13 mA cm−2 at 25 °C. This value is similar to the theoretical value.