Abstract: Electromagnetic interference (EMI) shielding materials with adaptive strain capability have broad applications in wearable electronic devices. However, as an important candidate, compressible conductive foam generally suffers from a reduction in EMI shielding performance during compression, which limits its application. Here, a compressible conductive aerogel with a unique conductive compensation effect is designed to solve this problem. CuS microspheres with metal-like conductivity serve as conductive compensation sites, and are chemically embedded in the skeletons of lamellar-structured carboxymethylcellulose (CMC)/MXene aerogel through Cu-S-Ti-C chemical bonds. The incorporation of CuS induces circularly-distributed interfacial polarization to enhance the attenuation of EM waves. More importantly, these CuS microspheres act as interlayer bridges to connect the upper and lower MXene/CMC layers during compression, thereby establishing numerous conductive compensation paths to offset the negative effect of thickness reduction on shielding performance. The optimized CMC/MXene/CuS aerogel shows stable EMI shielding performance during compression, and maintains a high shielding effectiveness of ∼32.31 dB with increasing compressive strain. In addition, this composite aerogel exhibits good thermal insulation and sound absorption performances, achieving triple shielding functions against EM waves, heat and sound.

Key words: Compressible conductive aerogel, Conductive compensation effect, Electromagnetic interference shielding, Thermal insulation, Sound absorption