Elastic Properties of New Solid State Electrolyte Material Li10GeP2S12: A Study from First-Principles Calculations

Abstract

Elastic properties of a new ultrafast lithium ion conductor Li10GeP2S12 were studied from first- principles calculations. The six independent elastic constants (C11, C12, C13, C33, C44, and C66) are obtained and the results satisfy the Born’s criteria of lattice stability. The bulk modulus B, shear modulus G, Young’s modulus E, elastic modulus X and Poisson’s ratio v were calculated to be 30.36 GPa, 14.35 GPa, 37.19 GPa, 20.80 GPa and 0.296, respectively. The B/G ratio is derived to be 2.12, implying that the Li10GeP2S12 is ductile according to Pugh’s criterion. The Van der Waals interactions are important in calculation of the elastic properties.