Screening of the alkali-metal ion containing materials from the Inorganic Crystal Structure Database (ICSD) for high ionic conductivity pathways using the bond valence method

Abstract

High ionic conductivity is one of the key characteristics of electrolytes and electrode materials directly affecting performance of electrochemical devices in which they are used. In the case of inorganic crystalline solid electrolytes and insertion cathodes the topology and geometry of crystal structure essentially defines ionic conductivity and charge–discharge rates. We employed the bond valence method to identify materials with crystal structures featuring infinite networks of pathways of suitable size that is a prerequisite for fast ion transport. Taking advantage of the method low computational cost, we carried out exhaustive analysis of ~13,000 entries of the Inorganic Crystal Structure Database and ranked the materials based on the fraction of crystal structure space with low bond-valence mismatch. The results may be used as a guide for further theoretical and experimental studies of promising compositions.