Dual Protective Porous Ti₃C₂T_x MXene/Polyimide Composite Film for Thermal Insulation and Electromagnetic Interference Shielding

Abstract The thriving 5G communication technology leads to the high demand for EMI shielding materials and thermal management materials. Particularly, portable thermal‐sensitive electronic devices have more stringent requirements for thermal insulation performances. In most cases, ultrathin EMI shielding materials integrated with ultralow thermal conductivity are not easy to be achieved. To overcome this obstacle, dual protective porous composite films based on Ti₃C₂T_x MXene and polyimide are fabricated by sacrificing polymethyl methacrylate (PMMA) templates. By optimizing the contact thermal resistance and Kapitza resistance, the composite film presents superior thermal insulation performances with a thermal conductivity of 0.0136 W m⁻¹ K⁻¹. Moreover, the hybrid porous film maintains superior EMI shielding effectiveness of 63.0 dB and high SSE/t of 31651.2 dB cm² g⁻¹. Nevertheless, the excellent active and passive heating ability based on Joule heating and photothermal conversion makes the composite film an ideal portable material for thermal management. This work sheds light on designing thermal management materials and EMI shielding materials for cutting‐edge electronic devices.