Comprehensive Analysis of Halogen-Rich Argyrodite Sulfides from a Multi-Level Perspective: Li-Ion Conduction and Elastic Modulus

We mapped and analyzed the correlation between Li-ion conductivity (σLi) and elastic modulus (E) of Li7–zPS6–zClz–xBrx (1.0 ≤ z ≤ 1.6, 0 ≤ x ≤ 1.6) with 42 different compositions from a multilevel perspective. In the as-milled glass-ceramics with low crystallinity, σLi remained around 1 mS cm–1 as the Br ratio increased, whereas E decreased to 12.59 GPa. In contrast, in the heat-treated samples with high crystallinity, σLi increased to 9.9 mS cm–1 with increasing Cl composition, and E increased sharply. Based on these results, we found exceptional regions (0.3 ≤ z – x ≤ 0.5, 0.9 ≤ x ≤ 1.1; 1.2 ≤ z – x ≤ 1.6, 1.4 ≤ z ≤ 1.6) containing both a lower modulus (E ≤ 18 GPa) and moderate conductivity (σLi ≥ 8 mS cm–1). Our results offer a chemo-mechanical perspective that can facilitate the development of next-generation solid-state electrolytes.