All-solid-state lithium-ion batteries are superior to conventional lithium-ion batteries in terms of energy density and safety risks and are currently of interest in battery research. For the investigation of solid-state Li-ion conductors a single-crystal state of the materials is preferable.

The study shows the growth of Li5.5La3Nb1.5Zr0.5O12, a garnet-type LLNZO Li-ion conductor with a quite promising ionic conductivity. It's the first report of a single crystal growth of a LLNZO with this Li content. The authors successfully grew this compound using the ScIDre HKZ-300 furnace of the PARADIM Bulk Crystal Growth facility at Johns Hopkins University.

Together with other previous single-crystal studies on higher Li compositions, this work establishes a more complete trend in this technically important class of materials.