Structures and Ion Conduction Pathways of Amorphous Lithium Ion Conductors

Abstract

For (⁷Li₂S)_x(P₂S₅)_100–x glasses (x = 50, 60, and 70) and ⁷Li₇P₃S₁₁ metastable crystal, time-of-flight neutron diffraction and synchrotron X-ray diffraction experiments were performed, and three-dimensional structures and conduction pathways of lithium ions were studied using the reverse Monte Carlo (RMC) modeling and the bond valence sum (BVS) approach. The conduction pathways of the lithium ions could be classified into two types: lithium “stable” and “metastable” regions, respectively. Moreover, it was found that there is a significant relationship between the activation energy of the electrical conduction and the topology of the conduction pathways of the lithium ions.