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

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.