Fluorinated amorphous halides with improved ionic conduction and stability for all-solid-state sodium-ion batteries

Designing halide solid electrolytes with high ionic conductivity and good (electro)chemical stability is essential for the advancement of all-solid-state sodium-ion batteries. Unfortunately, most sodium-based halide solid electrolytes experience limited ionic conductivities and ambiguous correlations between their structure features and ion transport properties. Here we report a design strategy to boost the conductivities of sodium halides by regulating vacancy and charge carrier concentrations through a facile Na- and Cl-deficient compositions method. This approach achieves a balanced structure with optimal vacancy and carrier content, rendering several-fold conductivities enhancement of series sodium…