Atomic-level designed LLZO electrolyte for LTO electrode in all-solid-state batteries with superb interfacial properties

Abstract

Li2TiO3 (LTO) is a promising electrode material with excellent electrochemical and non-toxic properties for storage of energy. However, the interfacial problem between LTO and solid electrolyte remains one of the key factors hindering their further developments. In this paper, first-principles calculation and ab initio molecular dynamics (AIMD) are conducted to explore the compatibility between LLZO solid-electrolyte and Li2TiO3 electrode for new class LTO-based all-solid-state batteries (ASSBs). Our results reveal that the LLZTO/LTO interface shows the highest interfacial formation energy and adhesion energy, which indicates the optimal interfacial stability and affinity among all the systems. Moreover, the diffusion barrier of lithium in LLZTO is much smaller than those of LLZYO and LLZNO, and the LLZTO/LTO interface show the best diffusion capability for lithium from 300 K to 500 K. It indicates that the number of vacancies created by doping of Ta is larger than those created by doping of Nb, Y elements.