Perfluoro Polyether Coated Chloride Solid Electrolytes Enable Stable All-Solid-State Batteries with Ultrahigh-Nickel Cathodes.

Cheng, Xiao-Bin; Zhao, Yulong; Hao, Xu-Dong; Hegazy, Ahmed M; Luo, Jin-Da; Tan, Hao-Yuan; Wang, Zi-Wei; Luo, Chen-Peng et al. · Nano Lett · 2026

basic_science · Level V

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Abstract

All-solid-state lithium batteries (ASSLBs) with ultrahigh-nickel cathodes offer high energy density and safety yet face challenges from poor interface compatibility under high voltage. This work reports a versatile strategy using perfluoro polyether (PFPE-COOH) to coat chloride solid electrolytes Li<sub>0.9</sub>NbO<sub>0.9</sub>Cl<sub>4.1</sub> (LNOC). Through simple ball milling, a uniform 1.2 nm coating is formed on LNOC, which maintains high ionic conductivity of 5.82 mS cm<sup>-1</sup> while effectively suppressing oxidative decomposition. Furthermore, PFPE-COOH significantly reduces the Young's modulus of LNOC from 3.78 to 1.53 GPa, enhancing mechanical flexibility to mitigate physical contact loss during cycling. ASSLBs using single-crystal LiNi<sub>0.92</sub>Co<sub>0.05</sub>Mn<sub>0.03</sub>O<sub>2</sub> cathodes and the modified LNOC exhibit exceptional stability, retaining 80.6% capacity after 400 cycles at a 4.6 V cutoff voltage. This study provides an effective interfacial engineering route for developing high-energy-density and long-cycling ASSLBs.