Revealing and stabalizing new polmorphs of halide solid electrolytes

This study investigates phase transitions in halide-based solid electrolytes (Na₂ZrCl₆, Li₂ZrCl₆, and their doped derivatives) and their impact on ionic conductivity using synchrotron X-ray diffraction (XRD) at BM01. We aim to correlate structural evolution with ion mobility by analyzing α→β→γ transitions and the formation of high-symmetry δ-phases. A key focus is whether Na-Li substitution and aliovalent doping (Y³⁺, In³⁺) can suppress phase transitions or stabilize high-conductivity monoclinic phases at ambient conditions. Additionally, uniaxial pressure will be explored to assess its role in stabilizing metastable states, inspired by stress-induced Martensitic transformations in Na₃YCl₆. Controlled heating/cooling experiments and impedance spectroscopy will link crystallographic changes to conductivity. The insights gained will accelerate the development of halide electrolytes with improved performance, addressing a critical bottleneck in solid-state battery technology.