High‐Entropy Tailored UCl 3 ‐Type Halides With Enhanced Ionic Conduction and Stability for All‐Solid‐State Sodium Batteries

Designing advanced halide-based solid electrolytes (SEs) combining high ionic conductivity and exceptional (electro)chemical stability is crucial for all-solid-state Na-ion batteries (ASSNIBs). However, most sodium-based halide systems remain restricted in high-voltage ASSNIB applications, due to their low conductivity from blocked ion-diffusion channels, and insufficient oxidation stability caused by anionic anti-oxidant bottlenecks. Here, we design a high‑entropy CeCl₃-based composi