Investigation of the effect of F-doping on the solid-electrolyte property of Li3InCl6

The effect of F-doping in Li3InCl6 is theoretically investigated using the first-principle methods. The simulations for the ionic transport property show that the energy barrier for Li-ion migration decreases near the position of the F ion in F-doped Li3InCl6, which improves Li-ion diffusivity by generating Li vacancies and promoting the vacancy diffusion mechanism. However, the F ion imposes a correlation effect on the Li-ion movement, which restricts the long-term travel range of the Li ions that are located near the F ion. These positive and negative effects of F-doping suggest that the F concentration should be precisely controlled for the optimum Li-ion con-ductivity of Li3InCl6. The thermodynamic study indicates that F-doping in Li3InCl6 is energetically unfavorable, but a kinetic possibility exists for the formation of the F-doped Li3InCl6 phase. However, the thermodynamic driving force for the segregation of F via the formation of a LiF phase still exists, which seems to be the origin of the LiF-based stable solid-electrolyte interphase layer formation when an F-doped Li3InCl6 is used as the elec-trolyte for all-solid-state Li batteries.

Automated summary

The effect of F-doping in Li3InCl6 was explored using first-principle methods. The simulation results indicated that F ion decreases the energy barrier for Li-ion migration, improving Li-ion diffusivity by promoting Li vacancies and the vacancy diffusion mechanism. However, F ion also restricts the long-term travel range of Li ions near it. Therefore, the F concentration should be precisely controlled for the optimum Li-ion conductivity. Thermodynamic study showed that F-doping is energetically unfavorable, but a kinetic possibility exists. The driving force for the segregation of F via the formation of a LiF phase is the origin of the stable solid-electrolyte interphase layer formation in F-doped Li3InCl6 for all-solid-state Li batteries.