Vertically Aligned Carbon Nanotube@Graphene Paper/Polydimethylsilane Composites for Electromagnetic Interference Shielding and Flexible Joule Heating

High-performance electromagnetic interference (EMI) shielding and thermal management materials with ultraflexibility, high strength, outstanding stability under mechanical deformation, and low cost are urgently demanded for modern integrated electronic and telecommunication systems. However, the creation and application of such desirable materials is still a potent challenge. Herein, we develop such a high-performance multifunctional multilayer composite, known as vertically aligned carbon nanotube@graphene paper/polydimethylsilane (VACNT@GP/PDMS), which involves the in situ growth of VACNTs onto GPs, vertical stacking of VACNT@GP layers, and infiltration of PDMS. The EMI shielding and mechanical properties of multilayer composites can be dramatically increased by increasing the number of VACNT@GP layers. Benefiting from the conduction loss in highly conductive GPs and polarization of huge VACNT–PDMS–VACNT microcapacitor networks, the multilayer composite with four VACNT@GP layers exhibits a superior EMI SE of 106.7 dB over a broad bandwidth of 32 GHz, covering the entire X-, Ku-, K-, and Ka-bands, which far suppresses the values of most of the reported EMI shielding materials. Moreover, the multilayer composites show excellent thermal management performance such as a high Joule-heating temperature at low supplied voltages, rapid response time, and sufficient heating stability. In addition, remarkable flexibility, high tensile strength (up to 13.4 MPa), and super stability under mechanical deformation (nearly no EMI SE degradation after repeatedly bending 10,000 times) are also discovered. These excellent comprehensive properties, along with the ease of low-cost mass production, pave the way for the practical applications of multilayer VACNT@GP/PDMS composites in EMI shielding and thermal management.