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

Abstract

We mapped and analyzed the correlation between Li-ion conductivity (sigma Li) and elastic modulus (E) of Li7-z PS6-z Cl z-x Br x (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, sigma Li 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, sigma Li 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 (sigma Li >= 8 mS cm-1). Our results offer a chemo-mechanical perspective that can facilitate the development of next-generation solid-state electrolytes.