Ab-initio simulation of novel solid electrolytes

Abstract

All solid-state batteries may be a solution to some of the problems facing conventional organic electrolytes in Li and Na-ion batteries, but typically conductivities are very low. Reports of fast lithium conduction in Li 0GeP 2S1 2 (LGPS), with conductivity of 12 mS/cm at room temperature, have shown that Li -diffusion in solid electrolytes can match or exceed the liquid electrolytes in use today. I report results of ab-initio calculations on a related system of materials, Nai0 MP 2SI 2 (M = Ge, Si, Sn), which are predicted to have similar properties to LGPS as candidates for electrolytes in Na-ion batteries. I also derive methods to estimate the error associated with diffusion simulations, so that appropriate tradeoffs between computational time and simulation accuracy can be made. This is a key enabler of a high throughput computational search for new electrolyte materials.