Multifunctional porous carbon fibers-based porous stacking for electromagnetic interference shielding

Developing electromagnetic interference (EMI) shielding materials with combinations of lightweight, multi-functions, and robust performance under harsh conditions, is urgent towards their practical application for portable electronic devices, while it still faces extreme challenges. In this work, porous carbon fibers (PCFs) featuring the interconnected nano-scaled pores on the surface and the internal micron-sized pores, were prepared and stacked into multi-layer carbon films, that further introduce the in-of-plane porous network and out-of-plane interlayer space. Such multi-scaled porous structure brings beneficial effects to carbon films including low density, consecutively conductive pathway, and outstanding capability to absorb electromagnetic waves. The produced carbon films exhibit remarkable electromagnetic interference shielding efficiency, achieving an attenuation level of up to 90 dB in the X band, even with a low material density of only 0.19 g/cm³. Furthermore, the stacked carbon films are structurally stable and robust, capable of delivering high EMI shielding performance under extreme environments, like acid/basic treatments, high (250 °C) or extremely cryogenic (−196 °C) temperatures and hygrothermal environments. Additionally, as-fabricated multi-layer carbon films demonstrate outstanding adsorption capacity for organic solvents and charge storage capacity. This work paves the way for multifunctional EMI materials construction in an economical and efficient manner.