ABSTRACT Lightweight and multifunctional electromagnetic interference (EMI) shielding materials are in urgent demand for advanced electronic devices used in harsh environments. In this work, honeycomb PIA‐Cu@MXene composite aerogels with excellent electromagnetic shielding and thermal properties were prepared through a synergistic strategy of cation–π interaction‐guided structural control, directional freeze‐drying, and repeated vacuum impregnation. Cu 2+ ‐mediated cation–π interactions contributed to a uniform and highly oriented honeycomb structure, which improved the mechanical robustness of the material. Meanwhile, uniformly dispersed Ti 3 C 2 T x MXene nanosheets constructed a continuous three‐dimensional conductive network. The aerogels exhibited outstanding absorption‐dominated EMI shielding performance in the X‐band. At 3 mm, the total shielding effectiveness (SE T ) of the optimized composite (PIC 0.2 M 6 with 20 mol% Cu 2+ and 6 mg mL −1 MXene suspension) was 22% higher than that of the copper‐free counterpart (PIC 0 M 6 ). The SE T reached 53.2 dB (specific shielding effectiveness SSE/ t ≈1642 dB cm 2 g −1 ) at 5 mm and 86.1 dB at 7 mm. The composite also possessed low thermal conductivity (~0.0511 W m −1 K −1 ) and good thermal stability, while maintaining stable shielding performance (SE T > 20 dB) under liquid‐nitrogen freezing, high temperature, and ultrasonic treatment. This study provides an effective structural and interfacial design for developing lightweight, mechanically stable polymer/MXene‐based EMI shielding materials with enhanced thermal management.
Yu et al. (Mon,) studied this question.