Atom substitution of the solid-state electrolyte Li10GeP2S12 for stabilized all-solid-state lithium metal batteries

Abstract

Solid-state electrolyte Li10GeP2S12 (LGPS) has a high lithium ion conductivity of 12 mS cm−1 at room temperature, but its inferior chemical stability against lithium metal anode impedes its practical application. Among all solutions, Ge atom substitution of the solid-state electrolyte LGPS stands out as the most promising solution to this interface problem. A systematic screening framework for Ge atom substitution including ionic conductivity, thermodynamic stability, electronic and mechanical properties is utilized to solve it. For fast screening, an enhanced model DopNetFC using chemical formulas for the dataset is adopted to predict ionic conductivity. Finally, Li10SrP2S12 (LSrPS) is screened out, which has high lithium ion conductivity (12.58 mS cm−1). In addition, an enhanced migration of lithium ion across the LSrPS/Li interface is found. Meanwhile, compared to the LGPS/Li interface, LSrPS/Li interface exhibits a larger Schottky barrier (0.134 eV), smaller electron transfer region (3.103 Å), and enhanced ability to block additional electrons, all of which contribute to the stabilized interface. The applied theoretical atom substitution screening framework with the aid of machine learning can be extended to rapid determination of modified specific material schemes.