Ultrathin Densified Carbon Nanotube Film with “Metal-like” Conductivity, Superior Mechanical Strength, and Ultrahigh Electromagnetic Interference Shielding Effectiveness

. Notably, the shielding effectiveness is over 51 dB with a thickness of merely 1.85 μm in the broad frequency range of 4-18 GHz, and it reaches to ∼82 dB at 6.36 μm and ∼101 dB at 14.7 μm, respectively. Further, such CNT film exhibits excellent reliability after an extended period in strong acid/alkali, high temperature, and high humidity. It demonstrates the best overall performance among representative shielding materials by far, representing a critical breakthrough in the preparation of shielding film toward applications in wearable electronics and 5G communication.