Synergistic Effects between MXenes and Ni Chains in Flexible and Ultrathin Electromagnetic Interference Shielding Films

Developing high-performance electromagnetic interference (EMI) shielding materials has become increasingly important along with the upcoming 5G communication era and the boom of wearable devices. However, the large thickness and poor mechanical properties of most of EMI shielding materials cannot satisfy the above critical requirements. Here, flexible and ultrathin poly(vinylidene fluoride) (PVDF)/MXene/Ni chain composite films are fabricated. Interestingly, by combining quasi-1D Ni chains and 2D MXenes, the average EMI shielding effectiveness of the PVDF/MXene/Ni chain composite films can reach 19.3 dB with only 0.10 mm thickness, and increases to 34.4 dB with 0.36 mm thickness. Besides, the tensile strength, Young's modulus, and toughness of the PVDF/MXene/Ni chain composite films are 41.9 ± 1.6 MPa, 1.18 ± 0.007 GPa, and 2.9 ± 0.08 MJ m⁻³, respectively. All of which are better than when using MXenes or Ni chains alone at the same loading. It is attributed to synergistic effects induced by unique 3D network constituted by MXenes and Ni chains. Moreover, the possible synergistic mechanisms for enhanced EMI shielding and mechanical properties are discussed. This work offers a promising solution for EMI shielding challenges in modern smaller and smaller wearable devices.