Title: Exploring La Substitution to Enhance Ionic Conductivity and Electrode Compatibility in Li₃YBr₆ for High-Performance Solid State Lithium BatteriesOral: Exploring La Substitution to Enhance Ionic Conductivity and Electrode Compatibility in Li₃YBr₆ for High-Performance Solid State Lithium Batteries

We present an exploration of the potential of La as a substitute for Y in Li3YBr6, known for high ionic conductivity and potential application in solid-state Li batteries. However, it was necessary to determine whether Li3LaBr6 exists, as it has not been reported. We attempted to grow single crystals from near-eutectic salt solutions while performing in situ measurements using a custom-built differential thermal analysis instrument. We observed crystals that grow in plate-like and rod-like habits under optical microscopy. We determined the lattice parameters of these crystals using a benchtop single-crystal x-ray diffractometer. Our data shows that Li3LaBr6 either does not exist or is not thermodynamically stable at temperatures near the eutectic melting point. We also discuss similar experiments with Y and Gd and the implications of alternative synthetic routes.