Speaker
Description
NASICON-type LiTi₂(PO₄)₃ is a promising solid electrolyte for all-solid-state lithium batteries due to its good thermal stability, structural durability, and three-dimensional lithium-ion conduction framework. However, its intrinsically low room-temperature ionic conductivity remains a major challenge for practical application. In this study, molecular dynamics simulations carried out with the DL_POLY code were used to investigate the structural and transport properties of bulk pristine, lithiated, and Al-doped LiTi₂(PO₄)₃. Lithiation and Al doping were examined to understand the effects of increased lithium content and framework modification on lithium-ion mobility. Lithium diffusion coefficients were obtained from mean square displacement calculations and used to determine ionic conductivity and activation energy. Ionic conductivities and activation energies were determined from the Nernst–Einstein equation and Arrhenius plots, respectively. The results revealed clear differences in lithium-ion transport among the bulk systems. The room-temperature ionic conductivity increased from 4.79 × 10⁻⁴ S/cm for LiTi₂(PO₄)₃ to 1.067 × 10⁻² S/cm for Li₃Ti₂(PO₄)₃ and 1.13 × 10⁻² S/cm for Li₁.₃Al₀.₃Ti₁.₇(PO₄)₃. Similarly, the activation energy decreased from 0.34 eV for LiTi₂(PO₄)₃ to 0.26 eV for Li₃Ti₂(PO₄)₃ and further to 0.16 eV for Li₁.₃Al₀.₃Ti₁.₇(PO₄)₃, indicating progressively easier lithium-ion migration across the series. These findings show that both lithium content and Al doping strongly influence transport behaviour in LiTi₂(PO₄)₃-based systems. While Li₃Ti₂(PO₄)₃ represents the lithium-inserted state relevant to cycling, Al doping produced the greatest improvement in ionic conductivity and the lowest migration barrier. This study provides atomistic insight into the role of lithium content and Al-doping in governing lithium-ion transport in NASICON-type LiTi₂(PO₄)₃ solid electrolytes, highlighting Al-doped LiTi₂(PO₄)₃ as the most promising candidate for improved solid-state battery performance.
| Apply for student award at which level: | MSc |
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| Consent on use of personal information: Abstract Submission | Yes, I ACCEPT |