摘要
As the next generation of commercial automotive power batteries begins replacing liquid lithium batteries,many look towards all-solid-state batteries to pioneer the future.All-so lid-state batteries have attracted the attention of countless researchers around the world because of their high safety and high energy density.In recent times,halide solid-state electrolytes have become a research hotspot within solid-state electrolytes because of their potentially superior properties.In this paper,in the framework of DFT,we investigated the atomic mechanisms of improving the ionic conductivity and stability of Li_(3)YbCl_(6).Our calculations show that both trigonal and orthorhombic Li_(3)YbCl_(6) exhibit wide electrochemical windows and metastable properties(100 meV/atom>Ehull>0 meV/atom).However,the orthorhombic Li_(3)YbCl_(6) can be stabilized at high temperatures by taking the vibrational entropy into account,which is supported by the experimental results.Moreover,it is expected that because of the Yb/Li synergistic interactions that,due to their strong mutual coulomb repulsion,influence the Li^(+)transport behavior,the orthorhombic Li_(3)YbCl_(6) might have superior ionic conductivities with appropriate Li+migration paths determined by the Yb^(3+) distribution.Also,higher ionic conductivities can be obtained by regulating the random distribution of Li^(+) ions.Further Li^(+)-deficiency can also largely increase the ionic conductivity by invoking vacancies.This study helps gain a deeper understanding of the laws that govern ionic conductivities and stabilities and provides a certain theoretical reference for the experimental development and design of halide solid-state electrolytes.
基金
Project supported by the GRINM Innovation Fund Project(2020TS0301)
Jilin Province Science and Technology Major Project(20210301021GX)
National Natural Science Foundation of China(U21A2080)。
