Synthesis and high Li-ion conductivity of Ga-stabilized cubic Li7La3Zr2O12

Ga addition to the garnet Li7La3Zr2O12 (LLZO) can lead to stabilization of the cubic structure, high relative density and high Li-ion conductivity at room temperature. Cubic Li6.25La3Zr2Ga0.25O12 powders were prepared from co-precipitated nitrate precursor and consolidated by hot-pressing to a relative density of ∼91%. The total Li-ion conductivity was ∼3.5 × 10−4 Scm−1 while the electronic conductivity was ∼7.1 × 10−8 Scm−1. The Ga substituted LLZO had a slightly higher total Li-ion conductivity compared to Al substituted LLZO of similar composition and relative density. This difference may be related to the larger size of Ga versus Al leading to different site occupancy fractions.