All solid state lithium-ion batteries further improve the safety and energy density of batteries on the basis of traditional lithium-ion batteries , It is expected to become an electric vehicle 、 Unmanned aerial vehicle (uav) 、 The next generation of a series of new industrial products such as wearable electronic devices “ Power source ”. The core component of all solid state lithium battery —— Solid electrolytes need high ionic conductivity 、 Electrochemical stability and other material properties , However, the types and quantity of sulfide and oxide solid electrolyte materials are limited , And the electrochemical window is narrow 、 The interface compatibility of cathode materials is poor 、 There are many challenges in terms of instability in the air and humid environment . So , With Li3YCl6 and Li3YBr6 Halide inorganic fast ionic conductor materials have gradually become a hot new star in the field of solid electrolyte .

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In the near future , University of Maryland Mo Yifei Professor team combines first principles computing and high-throughput screening , The conductivity of lithium ion in lithium chloride materials and its influencing factors are systematically studied , It is found that the cation arrangement and lithium ion content are the main factors affecting the conductivity of lithium chloride , Based on this, the guiding design principle of halide fast ionic conductor materials is put forward . In this study, molecular dynamics simulations based on density functional theory are used , More than ten kinds of chloride fast ionic conductors have been screened out , And then through the comparison of high 、 Structural characteristics of chloride materials with low ionic conductivity , Lithium ion content found 、 The cation content and the arrangement of cation sublattices are the main factors that affect the conductivity of lithium ion in chloride materials . Based on these factors , The team reverse engineered several early chloride materials with low ionic conductivity , The conductivity of chloride ion is greatly improved after design . The results show that the following three design principles are beneficial to improve the lithium ion conductivity of materials in chloride :(1) Keep the octahedral occupancy of lithium ion at a low level (40% - 60% Between );(2) Reduce the cation content in the material ;(3) Sublattice arrangement of cations in dispersion materials .
The team calculated from first principles , The conductivity of lithium ion containing lithium chloride is studied systematically , The design principle proposed and verified is expected to provide new guidance for halide solid fast ionic conductor materials in the future . The results are published in Advanced Energy Materials (DOI: 10.1002/aenm.202002356) On .

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