Speaker
Description
Lithium garnet oxides have been put forward as a solid-state alternative for Li-ion electrolytes since the Li$^{+}$ conducting abilities of Li$_{7}$La$_{3}$M$_{2}$O$_{12}$ (M = Ta, Nb) was discovered in 2003. [1] These solid state materials exhibit physical and chemical properties desired for more efficient and safer Li-ion battery electrolytes. [2] Lithium garnet oxides can exist in tetragonal and cubic phase isomorphs with the latter exhibiting higher conductivities. Li$_{7}$La$_{3}$Zr$_{2}$O$_{12}$ undergoes a phase transition from cubic to tetragonal due to the thermodynamic unstable nature of the cubic arrangement. [3] Ionic conductivities of up to 1 x 10$^{-3}$ S cm$^{-1}$ have been reported for cubic phase garnet materials of Li$_{6.4}$La$_{3}$Zr$_{1.4}$Ta$_{0.6}$O$_{12}$. [4] Here we present a dual doped garnet series of Li$_{6.75-3x}$Ga$_{x}$La$_{3}$Zr$_{1.75}$Ta$_{0.25}$O$_{12}$ and attempt to mimic the high conductivities seen in that Li$_{6.4}$La$_{3}$Zr$_{1.4}$Ta$_{0.6}$O$_{12}$. The successful synthesis of the proposed series was achieved via standard solid-state sintering from gallium doping up to x = 0.5. X-ray and neutron powder diffraction characterisation revealed that Ga has a preference to occupy the Li tetrahedral (Li24d) site over the octahedral (Li96h) site. High-temperature neutron diffraction studies show the relationship between temperature, Ga content, and Li displacement between the Li24d and Li96h sites.
References
[1]. V. Thangadurai, et al., Journal of the American Ceramic Society, 2003, 86, 437-440.
[2]. V. Thangadurai, et al., Chemical Society Reviews, 2014, 43, 4714-4727.
[3]. G. Larraz, et al., Journal of Materials Chemistry A, 2013, 1, 11419-11428.
[4]. M. M. Ahmad, et al., Journal of Materials Science: Materials in Electronics, 2015, 26, 8136-8142.
| Speakers Gender | Male |
|---|---|
| Level of Expertise | Student |
| Do you wish to take part in the poster slam | Yes |
