Structural stability and stabilization of Li2MoO3

Abstract

Due to its better physical and electrochemical properties, Li₂MoO₃ was proposed to replace Li₂MnO₃ for constructing new Li-rich cathode materials. However, the molybdenum (Mo)-ion shuttling between the Li layer and the Mo layer upon electrochemical Li-extraction raises concerns on the structural stability of the Mo-based Li-rich materials. In this article, the nudged energy band method was applied using first-principles calculations to understand the reason for the Mo-ion migration and to sieve substituent elements for Mo from a number of transition metals. Molecular dynamics calculations were performed to simulate the kinetic properties of the pristine and transition metal substituted Li₂MoO₃. On the basis of these calculations, antimony (Sb) was proposed as a substituent to enhance the structural stability of Li₂MoO₃ and improve its rate performance.