Solid polymer electrolytes (SPEs) by in situ polymerization are attractive due to their good interfacial contact with electrodes. Previously reported in situ polymerized SPEs, however, suffer from the low polymerization degree that causes poor mechanical strength, Li dendrite penetration, and performance decay in Li-metal batteries. Although highly polymerized SPEs are more stable than lowly polymerized ones, they are restricted by their sluggish long-chain mobility and poor ionic conductivity. In this work, a three-dimensional fibrous membrane with ion selectivity was prepared and used as a functional filler for the in situ formed SPE. The obtained SPE has high stability due to its high polymerization degree after the long-term heating process. The fibrous membrane plays a vital role in improving the SPE’s properties. The rich anion-adsorption sites on the fibrous membrane can alleviate the polarization effect and benefit a uniform current distribution at the interface. The fibrous nanostructure can efficiently interact with the polymeric matrix, providing rich hopping sites for fast Li⁺ migration. Consequently, the obtained SPE enables a uniform Li deposition and long-term cycling performance in Li-metal batteries. This work reported an in situ formed SPE with both high polymerization degree and ionic conductivity, paving the way for designing high-performance SPEs with good comprehensive properties.

通过原位聚合制备的固体聚合物电解质 (SPE)因其与电极的良好界面接触而极具吸引力。然而，先前报道的原位聚合 SPEs 存在聚合度低的问题，导致机械强度差、锂枝晶渗透和锂金属电池性能下降。虽然高聚合 SPE 比低聚合 SPE 更稳定，但它们受到长链流动性低和离子电导率差的限制。在这项工作中，制备了具有离子选择性的三维纤维膜，并将其用作原位的功能性填料。形成 SPE。所得SPE在长期加热过程后聚合度高，稳定性高。纤维膜在改善 SPE 的性能方面起着至关重要的作用。纤维膜上丰富的阴离子吸附位点可以减轻极化效应，有利于界面处均匀的电流分布。^{纤维状纳米结构可以有效地与聚合物基质相互作用，为 Li + 的}快速迁移提供丰富的跳跃位点。因此，获得的 SPE 能够在锂金属电池中实现均匀的 Li 沉积和长期循环性能。该工作报道了一种原位形成的同时具有高聚合度和离子电导率的SPE，为设计具有良好综合性能的高性能SPE铺平了道路。