Atomistic mechanism of high ionic conductivity in lithium ytterbium-based halide solid electrolytes:A first-principles study

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.

Self-assembly pre-occupancy for 2D super-ordered emptiness arrays in graphene

Self-assembly is deemed to be an effective and inspiring strategy to construct programmable and innovative super-ordered structures.Here,we have,for the first time,achieved the large-area super-ordered two-dimensional(2D)emptiness arrays in graphene by silicon dioxide self-assembly pre-occupancy.The prominent uniform periodicity of 2D emptiness arrays in graphene can be flexibly adjusted.The synergistic interaction between the pre-occupancy structural unit and graphene contributes to the successful acquisition of 2D emptiness arrays.The realization of 2D emptiness arrays by self-assembly pre-occupancy strategy would shed light on the rational redaction,fabrication and research of complex 2D super-ordered structure systems and facilitate their applications for various fields,such as highly integrated functional devices,precise location acquisition systems,sensing,separation,and so on.