With the rapid development of wireless communication technology and electronic devices, the issue of electromagnetic interference (EMI) is becoming increasingly severe. Developing a new and flexible electromagnetic interference shielding material has become a challenging task. Here, a sandwich-structured EMI shielding composite film was prepared using electrospinning and vacuum filtration methods. In this process, a porous MXene was synthesized through a reaction with cobalt acetate and served as the intermediate layer in the composite film to shield electromagnetic waves. The electrospun polyimide (PI) fibers were used as the top and bottom layers of the composite film, which can protect the porous MXene from oxidation. This lightweight and flexible composite film integrates electromagnetic interference shielding and thermal insulation capabilities, showing excellent comprehensive performance. The composite film achieves an EMI shielding effectiveness of 48.8 dB in X-band (8.2–12.4 GHz), and absolute shielding effectiveness of the composite film reached a satisfying 4142.43 (dB·cm²)/g. Owing to the design of a multi-layer porous structure, the density of the composite film is 0.65 g/cm³. Furthermore, the thermal conductivity of the film is 0.042 W/(m·K) due to the clamping of electrospun PI fibers, showing excellent thermal insulation performance. Additionally, the composite film exhibits excellent high and low-temperature resistance. In summary, this work provides a feasible strategy for preparing a lightweight polymer-based EMI shielding film.

随着无线通信技术和电子设备的快速发展，电磁干扰（EMI）问题变得日益严重。开发新型柔性电磁干扰屏蔽材料已成为一项具有挑战性的任务。本文采用静电纺丝和真空过滤方法制备了三明治结构的 EMI 屏蔽复合薄膜。在此过程中，通过与醋酸钴反应合成了多孔MXene，并作为复合膜中屏蔽电磁波的中间层。电纺聚酰亚胺（PI）纤维用作复合膜的顶层和底层，可以保护多孔MXene免受氧化。这种轻质柔性复合薄膜集电磁干扰屏蔽和隔热功能于一体，表现出优异的综合性能。复合薄膜在X波段（8.2~12.4 GHz）的EMI屏蔽效能达到48.8 dB，复合薄膜的绝对屏蔽效能达到令人满意的4142.43（dB·cm ²）/g。由于多层多孔结构的设计，复合膜的密度为0.65g/cm ³。此外，由于静电纺PI纤维的夹紧，薄膜的导热系数为0.042 W/(m·K)，表现出优异的隔热性能。此外，该复合膜还具有优异的耐高低温性能。总之，这项工作为制备轻质聚合物基 EMI 屏蔽薄膜提供了可行的策略。