Integrated study of first principles calculations and experimental measurements for Li-ionic conductivity in Al-doped solid-state LiGe2(PO4)(3) electrolyte
- Title
- Integrated study of first principles calculations and experimental measurements for Li-ionic conductivity in Al-doped solid-state LiGe2(PO4)(3) electrolyte
- Author(s)
- Kang, J[Kang, Joonhee] ; Chung, H[Chung, Habin] ; Doh, C[Doh, Chilhoon] ; Kang, B[Kang, Byoungwoo] ; Han, B[Han, Byungchan]
- DGIST Authors
- Kang, J[Kang, Joonhee] ; Han, B[Han, Byungchan]
- Issued Date
- 2015-10-20
- Type
- Article
- Article Type
- Article
- Subject
- Ab Initio Molecular Dynamics ; Activation Energy ; Aluminum ; Atoms ; Calculations ; Chemical Activation ; Density Functional Theory ; Diffusion Mechanism ; Diffusion Mechanisms ; Electrolytes ; First-Principles ; First-Principles Calculation ; First Principles Density Functional Theory (DFT) Calculations ; Germanium ; Ionic Conduction In Solids ; Ionic Conductivity ; Li-Ion Batteries ; Lithium ; Lithium-Ion Batteries ; Molecular Dynamics ; Nudged Elastic Band Methods ; Solid-State Electrolyte ; Solid Electrolytes
- ISSN
- 0378-7753
- Abstract
-
Understanding of the fundamental mechanisms causing significant enhancement of Li-ionic conductivity by Al3+ doping to a solid LiGe
2 (PO4 )3 (LGP) electrolyte is pursued using first principles density functional theory (DFT) calculations combined with experimental measurements. Our results indicate that partial substitution Al3+ for Ge4+ in LiGe2 (PO4 )3 (LGP) with aliovalent (Li1+x Alx Ge2-x (PO4 )3 , LAGP) improves the Li-ionic conductivity about four-orders of the magnitude. To unveil the atomic origin we calculate plausible diffusion paths of Li in LGP and LAGP materials using DFT calculations and a nudged elastic band method, and discover that LAGP had additional transport paths for Li with activation barriers as low as only 34% of the LGP. Notably, these new atomic channels manifest subtle electrostatic environments facilitating cooperative motions of at least two Li atoms. Ab-initio molecular dynamics predict Li-ionic conductivity for the LAGP system, which is amazingly agreed experimental measurement on in-house made samples. Consequently, we suggest that the excess amounts of Li caused by the aliovalent Al3+ doping to LGP lead to not only enhancing Li concentration but also opening new conducting paths with substantially decreases activation energies and thus high ionic conductivity of LAGP solid-state electrolyte. © 2015 Published by Elsevier B.V.
- Publisher
- Elsevier B.V.
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- Appears in Collections:
- Department of Energy Science and Engineering Energy Systems Engineering 1. Journal Articles
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