Realizing Ultrahigh Fatigue Resistance in Carbon Nanotube Aerogel by Homogeneous‐Phase Hybrid Core‐Sheath Structure

ABSTRACT Carbon materials are promising candidates for building lightweight, high‐strength, fatigue‐resistant structural materials. However, they are generally plagued by the assembling dilemmas, whereby the intrinsic properties at the nanoscale weaken sharply at the macroscale, which severely limits their applications. Here, a natural tree‐inspired designing strategy, for fabricating highly compressible and fatigue‐resistant aerogels by assembling intrinsic anti‐fatigue carbon nanotubes with homogeneous‐phase and organic–inorganic hybrid sheath, is proposed. This assembled aerogel realized an ultrahigh fatigue resistance over one million compression cycles at a large deformation of 50% (less than 4.2% permanent deformation and 6.6% stress loss), which has never been achieved in porous materials. A modulus loss‐dominated fatigue behavior, derived from the hybrid homogeneous‐phase sheath which suppresses joint damage and crack initiation, was disclosed via long‐term fatigue tests. Additionally, it is further demonstrated that the aerogels can be utilized as anti‐mechanical impact structural material and efficient terahertz shielding/absorption materials that can serve in different extreme‐temperature scenarios. This work not only offers a design strategy to develop elastic and fatigue‐resistant aerogels, but also provides a perspective to realize excellent intrinsic properties of nanomaterials in macroscopic assembly.