Amorphous Nitride‐chloride Solid‐State Electrolytes for High Performance All‐Solid‐State Lithium Batteries

Abstract High‐performance solid‐state electrolytes (SSEs) are crucial for advancing all‐solid‐state batteries (ASSBs). Amorphous SSEs, in particular, offer promising advantages due to their grain‐boundary‐free nature, which facilitates intimate solid‐to‐solid contact and uniform lithium‐ion flux, thereby improving composite electrode performance. Here, we report a class of SSEs based on a nitrogen–chlorine dual‐anion framework, formulated as Li 3 x +0.1 ZrN x Cl 4.1 , for high‐voltage ASSBs. Unlike widely studied crystalline Li 2 ZrCl 6 with a triclinic structure, increased N 3− substitution drives a structural transition to an amorphous phase (Li 1.3 ZrN 0.4 Cl 4.1 ), which achieves a significant enhancement in Li + conductivity from 0.46 to 3.01 mS cm −1 , alongside improved oxidative stability up to 4.8 V. This dual‐anion SSEs exhibits excellent compatibility with high‐energy LiNi 0.83 Co 0.06 Mn 0.11 O 2 (NCM83) cathodes. The corresponding full cells deliver a high reversible capacity of 200.1 mAh g −1 at 4.5 V with outstanding capacity retention of 95.1% after 150 cycles at 0.2 C, along with remarkable long‐term cycling stability exceeding 3000 cycles at 3 C. Furthermore, the electrochemical stability of Li 1.3 ZrN 0.4 Cl 4.1 in conjunction with NCM83 is still preserved under elevated temperatures (50 °C) and higher cut‐off voltages (up to 4.8 V). These results highlight the promise of dual‐anion amorphous electrolytes, paving the way for the design of next‐generation SSEs beyond traditional single‐anion systems.