Highly stretchable and conductive 3D graphene skeleton/polyacrylamide/LiCl nanocomposite hydrogels for high-performance electromagnetic interference shielding

The rapid development of next-generation flexible electronic devices and soft robotics urgently requires highly stretchable and conductive electromagnetic interference (EMI) shielding materials to address interference from electromagnetic radiation. Herein, we develop highly stretchable and electrically conductive EMI shielding hydrogels based on three-dimensional graphene skeleton/polyacrylamide/LiCl (3DGS/PAM) hydrogels. The resultant 3DGS/PAM nanocomposite hydrogels exhibit superior stretchability (610 % strain), high conductivity (9.3 S/m), outstanding EMI shielding efficiency (EMI SE) (48.4 dB), excellent freezing resistance (-25 °C), and moisturizing retention properties (118 wt% after 10 days) due to the unique recoverable conductive network and movable ions. Benefitting from the excellent synergistic effects of 3DGS, lithium chloride, and PAM hydrogels, the 3DGS/PAM nanocomposite hydrogels maintain stable electrical conductivity ( Δ R / R 0 < 115 %) after 1000 stretching-releasing cycles with 200 % strain. The interconnected conductive network and water molecules endow the hydrogels with excellent EMI shielding stability, maintaining an EMI SE value of 34 dB at a strain of 50 % and 20.5 dB at a large strain of 200 %. With superior conductivity, EMI shielding performance, outstanding stretchability, and reliability, the 3DGS/PAM nanocomposite hydrogels demonstrate promising potential to design stretchable EMI shielding materials for flexible devices and wearable electronics.