Li29Zr9Nb3O40 based Li-ionic conductors as a new system of solid-state electrolytes

Abstract Taking into account of high energy density and safety, solid-state lithium-ion batteries (LIBs) are promising for next-generation energy storage devices and high-performance power sources, and the inorganic solid electrolyte is a key component in LIBs. Here, a new system of solid oxide electrolyte with a nominal composition of Li29Zr9Nb3O40 (LZNO) and Al-doped LZNO are prepared through a sol-gel method and the related ionic conductivities are firstly investigated. All the prepared compounds have an orthorhombic structure. The pure LZNO shows a bulk conductivity of 1.75 × 10−4 S cm−1 and a total conductivity of 5.90 × 10−5 S cm−1 at 25 °C, and has low activation energy of conduction of 0.20 eV. The Al-doping enhances the total ionic conductivity up to 2.41 × 10−4 S cm−1 at room temperature. The computational simulation by using bond valence site energy reveals that the LZNO crystal has 3D migration pathways including two-dimensional migration pathways along a- and c- orientations, as well as the migration b-direction one provided by the partially occupied O (8) sites.