Solid‐state polymer electrolytes (SPEs) require high ionic conductivity and dense contact with the electrodes for high‐performance lithium‐metal solid‐state batteries. However, massive challenges such as poor ionic migration ability, low antioxidant ability, and lithium dendrite formation still remain unresolved. These issues severely restrict its practical applications. Herein, a new type of solid‐state polymer electrolyte with a molecular crowding feature is rationally designed by in situ polymerization of a precursor containing poly (ethylene glycol) diacrylate (PEGDA) and 1,2‐dimethoxyethane (DME). Noticeably, the prepared SPE expands the electrochemical window to 4.7 V with a high lithium‐ion transfer number of 0.55 and a superior ionic conductivity of 3.6 mS cm−1 at room temperature. As a result, the lithium symmetrical batteries achieve stable cycles with more than 3000 h with no lithium dendrites at a current density of 0.5 mA cm−2. Importantly, this design provides dense contact of solid‐state polymer electrolytes with the porous cathode and lithium anode, allowing the assembled winding‐type solid‐state pouch cells with outstanding cycling stability of 81.7% retention for more than 340 cycles at room temperature. It shows excellent adaption to widely practical technology with large‐scale battery production, offering a new solution for the future development of solid‐state polymer lithium‐metal batteries.

中文翻译：

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原位聚合法制备锂金属电池分子拥挤固体聚合物电解质


固态聚合物电解质 （SPE） 需要高离子电导率和与高性能锂金属固态电池电极的紧密接触。然而，离子迁移能力差、抗氧化能力低和锂枝晶形成等巨大挑战仍未解决。这些问题严重限制了它的实际应用。在此，通过对含有聚乙二醇二丙烯酸酯 （PEGDA） 和 1,2-二甲氧基乙烷 （DME） 的前驱体进行原位聚合，合理设计了一种具有分子拥挤特征的新型固态聚合物电解质。值得注意的是，制备的 SPE 将电化学窗口扩展到 4.7 V，在室温下具有 0.55 的高锂离子转移数和 3.6 mS cm−1 的优异离子电导率。因此，锂对称电池在 0.5 mA cm-2 的电流密度下实现了超过 3000 h 的稳定循环，且没有锂枝晶。重要的是，这种设计提供了固态聚合物电解质与多孔阴极和锂阳极的紧密接触，使组装的绕组型固态软包电池在室温下具有 81.7% 的出色循环稳定性，可循环超过 340 次。它对大规模电池生产的广泛实用技术表现出优异的适应性，为固态聚合物锂金属电池的未来发展提供了新的解决方案。