Customize Aramid Nanofiber Aerogels with High Electromagnetic Shielding Performance from Ultra‐Malleable Kevlar‐Derived Jelly

Abstract It is important but challenging to develop high‐performance electromagnetic interference (EMI) shielding materials with customizable structures, tailorable properties, light weight, and high‐efficiency EMI shielding effectiveness (SE). Herein, a facile approach is proposed to customize aramid nanofiber (ANF) based EMI shielding aerogels with pre‐designed architectures through ultra‐malleable ANF jellies. By precisely regulating the interfiber interactions between ANF and constructing a robust 3D skeleton, ANF jelly can be ‘kneaded‐frozen‐heated’ like dough to produce ultralight, elastic and porous ANF aerogels with special structures, such as aerogel sandwich, spring, fabric, etc. Benefiting from the interconnected porous structure, conductive fillers such as silver nanowires (AgNW) can easily cover the aerogel skeleton by dip‐coating to form highly conductive paths. With an ultra‐low loading (7.5 wt.%) of AgNW, a 5.2 mm‐thick AgNW/ANF aerogel exhibit an average EMI SE of 75.4 dB in the X‐band. Aerogels with additional functions can be customized according to the actual application environment. A customized sandwich aerogel with fire‐retardant outerlayer and EMI shielding interlayer can be used in high‐temperature environments. A flexible aerogel fabric as an EMI shielding gasket can effectively block wireless power transmission. This work provides a forward‐looking strategy for constructing high‐performance EMI shielding materials with tailored properties.