Poly(ethylene oxide) (PEO) as a solid‐state electrolyte faces critical limitations, including low ionic conductivity, a narrow electrochemical window, and poor mechanical strength. To address these issues, flaky lithium‐doped high‐entropy oxides (LHEO‐f) with abundant surface oxygen vacancies are synthesized via a facile microwave‐assisted deep eutectic solvent (DES) method and incorporated into PEO‐based composite solid electrolytes (CSEs). The flaky LHEO‐f fillers morphology increases the continuous contact surface area with polymer chains, while oxygen vacancies enhance interfacial interactions. This synergy diminishes polymer deformation and enhances the mechanical strength of the CSEs. Moreover, the surface defects of LHEO‐f improve interactions with the oxygen‐containing groups of the polymer matrix, facilitating Li‐ion migration. All‐solid‐state lithium metal batteries (ASSLMBs) with these CSEs demonstrate excellent high‐rate capacity and cycling stability. These findings reveal that the incorporation of LHEO‐f significantly bolsters the performance of PEO‐based CSEs, showcasing their potential for further advancement and practical application in the realm of solid‐state batteries.

中文翻译：

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片状掺锂高熵氧化物使基于 PEO 的复合固体电解质具有更长的锂金属电池适用性


聚环氧乙烷 （PEO） 作为固态电解质面临严重限制，包括离子电导率低、电化学窗口窄和机械强度差。为了解决这些问题，通过简单的微波辅助深共晶溶剂 （DES） 方法合成了具有丰富表面氧空位的片状锂掺杂高熵氧化物 （LHEO-f），并将其掺入基于 PEO 的复合固体电解质 （CSE） 中。片状 LHEO-f 填料形态增加了与聚合物链的连续接触表面积，而氧空位增强了界面相互作用。这种协同作用减少了聚合物变形并增强了 CSE 的机械强度。此外，LHEO-f 的表面缺陷改善了与聚合物基质的含氧基团的相互作用，促进了锂离子迁移。带有这些 CSE 的全固态锂金属电池 （ASSLMB） 表现出优异的高倍率容量和循环稳定性。这些发现表明，LHEO-f 的加入显着提高了基于 PEO 的 CSE 的性能，展示了它们在固态电池领域进一步发展和实际应用的潜力。