Enhancing thermal conductivity, electromagnetic interference shielding, and joule heating in polyether ether ketone composites using three-dimensional scaly carbon fibre structures and structural optimisation

Carbon fibre-reinforced polymer composites are crucial in aerospace and defence applications. This study reports a polyether ether ketone composite reinforced with scaled heterogeneous fibres, including graphene nanosheets, multi-walled carbon nanotubes, and nickel-plated carbon fibres. The composite features a prefabricated threedimensional thermal conductive network, achieving in- and through-plane thermal conductivities of 11.91 and 3.25 W/(m center dot K), respectively, an electrical conductivity of 9364 S/m, and an electromagnetic interference shielding effectiveness of 85.93 dB. The composite reaches a Joule heating temperature of 252.4 degrees C under 3 V while maintaining excellent mechanical properties. This performance is attributable to the ordered network framework established by the submillimetre heterogeneous fibre fillers, enhanced electron transport via electroplated nickel nanometals, and 3D hybrid filler network. Optimising the filler distribution further improves the composite, achieving in- and through-plane TCs of 18.28 and 9.66 W/(m center dot K), respectively, an electrical conductivity of 16,492 S/m, EMI shielding effectiveness of 132.06 dB, and Joule heating of 285.5 degrees C. Finite element analyses highlight the advantages of these fillers and optimised matrix structure in enhancing thermal transfer and Joule heating. This study provides a design strategy for multifunctional composites in advanced electronic devices.