Modulating Local Structure of Amorphous Oxyhalide to Achieve High‐Rate and Ultra‐Stable All‐Solid‐State Lithium Battery

Halides‐based all‐solid‐state lithium batteries (ASSLBs) attract great attention because of their wide electrochemical window and fine processibility. However, low ionic conductivity of halides and solid‐solid interface incompatibility result in inferior rate capability and poor cycling stability. Herein, we modulate local structure (short‐range‐structure disorder degree, coordination diversity, and so forth) via a synergistic anion–cation strategy to achieve amorphous solid electrolyte 1.6Li 2 O‐TaCl 5 ‐0.3MgF 2 (LTOC‐M) with a high ionic conductivity (11.15 mS cm −1 ) and favorable interfacial compatibility. F incorporation at Cl/O sites strengthens Ta─F bonding and Li–F interactions, enhancing long‐term cycling stability, while Mg incorporation modulates the local cationic environment, increases coordination diversity, and facilitates Li + transport within the amorphous matrix. ASSLBs with LiNi 0.8 Co 0.1 Mn 0.1 O 2 or LiCoO 2 demonstrate superhigh rate capability and long‐term cycling stability (LiNi 0.8 Co 0.1 Mn 0.1 O 2 :92.29%@4000cycles@5C; LiCoO 2 :80.85%@5000cycles@10C). When paired with Li‐rich Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 , the cell delivers a high initial capacity of 270.38 mAh g −1 with a cycling stability (92.75%@120cycles@0.2C). Moreover, Li‐In| Li 6 PS 5 Cl‐LTOC‐M|LiCoO 2 delivers a high discharge capacity of 128.80 mAh g −1 at −20°C and demonstrates a cycling stability (96.62%@550cycles@0.2C), and the battery functions even at −75°C for over 400 h. The proposed strategy effectively enhances high‐rate performance, long‐term cycling stability and low‐temperature performance of halides‐based ASSLBs, accelerating their practical application.