Amorphization Engineering via Multi‐Anion Doping Toward Fast Li + Transport and Conformable Interfaces for Stable Solid‐State Batteries

ABSTRACT Solid‐state electrolytes (SSEs) are key to enabling all‐solid‐state batteries (ASSBs) with high‐energy density, enhanced safety, and long‐term durability. However, conventional inorganic SSEs with high crystallinity usually suffer from insufficient ionic conductivity, poor deformability, and unstable interfacial contact with electrodes, which severely hinder their long‐term cycling performance. Herein, we report the design of an amorphous multi‐anion‐doped solid electrolyte, Li 2.4 ZrCl 4 OF 0.1 N 0.1 (OFN), synthesized by a simple ball‐milling method. It is revealed that a multi‐anion coordinated structure endows the amorphous OFN solid electrolyte with fast Li + transport kinetics and superior mechanical deformability, facilitating conformal interfacial contact with the cathode electrodes. As a result, the OFN solid electrolyte achieves desirable ionic conductivities up to 2.73 mS cm −1 at 25°C with a wide electrochemical window of 2.2–4.2 V. Furthermore, this enables exceptional rate performance and cycling stability of the assembled OFN‐based ASSBs, maintaining 80% capacity retention for 900 cycles at 1 C, when coupled with LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathode. This study provides a new avenue in designing high‐performance amorphous SSEs through a multi‐anion doping strategy for advancing next‐generation ASSBs.