A Triple‐Network Aerogel Composite With Thermally Induced Phoenix‐Like Transformation: From Elastic Ablation Resistance to Efficient EMI Shielding

ABSTRACT The rapid advancement of space science and technology poses severe challenges for deep space probes operating in extreme thermo‐electromagnetic environments. However, traditional rigid aerospace materials lack sufficient deformation adaptability and cannot integrate thermal protection with electromagnetic interference (EMI) shielding. To overcome these limitations, we developed a Triple‐Network aerogel composite with thermally induced “Phoenix‐like” transformation, which was fabricated through a molecular‐scale covalent‐coordination strategy. The resulting titanium‐boron‐silicon phenolic aerogel (T‐BS‐PRf) features a triple cross‐linked interpenetrating network, which gives it an ultralow density of ≈0.204 g/cm 3 , excellent elasticity (>92% recovery at 50% strain), and a strength of 1.97 MPa and overcomes the typical strength–elasticity trade‐off. The composite also exhibits outstanding thermal insulation and ablation resistance, maintaining structural integrity with a very low linear ablation rate of 0.00279 mm/s after 30 min under a 1300°C flame. Notably, ablation triggers an in situ ceramic transformation, yielding a porous carbon aerogel (T‐BS‐Cf) that provides outstanding EMI shielding (92.8 dB in the X‐band) and retains robust mechanical properties (8.62 MPa strength, elasticity recovery 94.7% at 40% strain). This work successfully integrates high elasticity, extreme thermal protection, and effective EMI shielding in a single composite, offering a new design strategy for multifunctional spacecraft in extreme environments.