Datensatz

Zusammenfassung

The lithium thiophosphate material class provides promising candidates for solid state electrolytes in lithium ion batteries due to high lithium ion conductivities and low material cost.
Theoretical ab-initio studies probing lithium ion conductivity are constrained in system size and simulated time scales. This limits the transferability of their results to real-world materials in the structure class. Those are characterized by complex thiophosphate microchemistry and grain boundaries influencing the material performance. A method with reduced computational cost, which nevertheless reproduces the material’s complex chemistry, would hence be highly desirable. We present the development of a near-universal atomistic potential for the LPS
material class employing Gaussian process regression. The atomistic potential can describe likewise crystal and glassy materials and different P-S connectivities (P_mS_n). Furthermore, we apply the ML potential with the aim to probe lithium ion conductivity. The materials studied are crystals (modifications of Li₃PS₄ and Li₇P₃S₁₁), glasses of the x Li₂S-(100 - x)P₂S₅ type (x = 67, 70 and 75) and glass-ceramic interfaces.
The obtained material properties for likewise crystals and glasses show a good agreement with results from theory and experiment. For the amorphous materials, the effects of thiophosphate microchemistry and Li₂S content on lithium ion conductivity were explicitly investigated. No influence was found for the former, but ion conductivity increases alongside the latter one.