MOF-derived CoNi@C-silver nanowires/cellulose nanofiber composite papers with excellent thermal management capability for outstanding electromagnetic interference shielding

High-performance electromagnetic interference (EMI) shielding materials with excellent flexibility and superior thermal management properties are ideal candidates for aerospace, communication industry, artificial intelligence, and wearable electronics. Herein, MOF-derived CoNi@C-silver nanowires/cellulose nanofiber (MAg/CNF) composite papers with Janus structure were prepared using a combination of two-step vacuum filtration and hot pressing. The resulting composite papers exhibit distinct electrical differences on both sides. The electrical conductivity of the CoNi@C/CNF side is 8.35 × 10⁻¹² S/cm, while that of the AgNWs/CNF side is 990 S/cm. EMI shielding effectiveness (SE) of the MAg/CNF composite papers reaches 82 dB in the X-band, benefiting from effective double-layer structure, the AgNWs conductive network and the CoNi@C permeability network for adequate dissipation of electromagnetic waves. Excellent EMI shielding performance is maintained even after being subjected to low temperature of −196 °C and bending cycles of 1000 times. In addition, the MAg/CNF composite paper-based electric heaters exhibit satisfactory heating temperatures at absolutely safe operating voltages for the human as well as sufficient stability and repeatability during repeated heating and cooling cycles. Therefore, our fabricated MAg/CNF composite papers with Janus structure present broad application prospects for high-performance EMI shielding and thermal management in low-temperature environment.