Sandwich-structured multifunctional composite films with excellent electromagnetic interference shielding and light/electro/magnetic-to-thermal conversion and storage capabilities

Portable and wearable materials with anti-electromagnetic interference (EMI), effective thermal management, stability and durability are sought after in the modern electronics industry, and yet remain extremely challenging to develop. Herein, a simple alternating vacuum-assisted filtration method was proposed to prepare sandwich-structured PVA/MXene/Ag NWs/PCCs composite films, which subtly integrates the thermal management functions of phase-change microcapsules (PCCs) with the electromagnetic shielding of MXene and Ag NWs. The obtained film retains the high enthalpy value (165.7 J/g) and exhibits excellent EMI shielding effectiveness (69.24 dB) in the X-band simultaneously. In addition, multilayer sandwich-structured films were introduced to improve thermal conductivity and flexibility. More importantly, these films can efficiently convert solar, electrical, and magnetic energy into thermal energy, and store them as latent heat generated by PCCs, thus broadening service scenarios. Therefore, this work provides a new strategy for constructing MXene-based wearable devices with excellent EMI shielding and thermal management.