Solid polymer electrolytes (SPEs) with in-built inorganic fillers are very promising for building safe solid-state batteries, owing to their excellent flexibility, prominent interfacial wettability and low costs. However, the morphology and surface state of inorganic fillers greatly affect ionic conductivity of SPEs. Here, we report that ultraviolet (UV) initiates in situ cross-linking of poly(ethylene glycol) methyl ether acrylate (MPEGA), poly(ethylene glycol) diacrylate (PEGDA) and montmorillonite (MMT) between cathodes and anodes of cell, to produce a solid composite electrolyte (CMP/MMT) that is composed of a robust interpenetrating polymer network matrix and layered MMT nanosheets. Surprisingly, the CMP/MMT delivers a high room-temperature ionic conductivity (~1.06 mS cm⁻¹), large lithium-ions transference number (t_Li+ = 0.79). The large ionic conductivity enhancement is ascribed to the local electric field effect of montmorillonite (MMT), which accelerates the lithium-ions fast transport in the interlayer of the MMT nanosheets. In addition, the density functional theory (DFT) is conducted to demonstrate the mechanism of improving ionic conductivity. As a result, a solid-state battery with CMP/MMT demonstrates a high capacity of ~140 mAh g⁻¹ and excellent capacity retention of >98% at 0.3 C after 400 cycling.

具有内置无机填料的固体聚合物电解质（SPE）由于其优异的柔韧性、显着的界面润湿性和低成本，在构建安全的固态电池方面非常有前景。然而，无机填料的形态和表面状态极大地影响了 SPE 的离子电导率。在这里，我们报告说，紫外线 (UV) 引发了电池阴极和阳极之间的聚（乙二醇）甲基醚丙烯酸酯（MPEGA）、聚（乙二醇）二丙烯酸酯（PEGDA）和蒙脱石（MMT）的原位交联，以生产固体复合电解质 (CMP/MMT)，由坚固的互穿聚合物网络基质和层状 MMT 纳米片组成。令人惊讶的是，CMP/MMT 提供了高室温离子电导率（~1.06 mS cm ^-1)，大的锂离子转移数 (t _Li+ = 0.79)。较大的离子电导率增强归因于蒙脱石（MMT）的局部电场效应，它加速了锂离子在 MMT 纳米片层间的快速传输。此外，还进行了密度泛函理论（DFT）来证明提高离子电导率的机制。因此，具有 CMP/MMT 的固态电池在 400 次循环后表现出约 140 mAh g ^-1的高容量和在 0.3 C 下 >98% 的出色容量保持率。