Asymmetric impedance structured Ni@CoFe2O4@CNTs aerogel composite for high electromagnetic shielding and infrared stealth performance

In modern battlefield scenarios, electromagnetic interference (EMI) from dense electronic systems and radar detection, together with infrared (IR) thermal imaging surveillance, impose dual threats to the survivability of military assets. Accordingly, advanced materials capable of simultaneously delivering high-efficiency EMI shielding and effective IR stealth are in urgent demand. Herein, we propose an asymmetric impedance-matched Ni@CoFe 2 O 4 @CNTs aerogel composite, in which one side consists of a porous CoFe 2 O 4 @CNTs aerogel (absorption layer) with an optimized mass ratio of 2:1, achieving favorable impedance matching ( Z  ≈ 1) and a high absorption coefficient (A = 0.77). And the other side is coated with a dense nickel layer via selective electroless plating, acting as a reflective layer with low infrared emissivity (0.487) to re-reflect transmitted electromagnetic waves. This asymmetric architecture establishes an “absorption–reflection–reabsorption” attenuation pathway, yielding an EMI shielding effectiveness (SE T ) of 43.95 dB across the X-band and an A/R ratio of 3.55, which verifies an absorption-dominated shielding mechanism. Meanwhile, the nickel coating reduces surface IR emissivity, while the porous aerogel serves as a thermal insulator, lowering the equilibrium surface temperature to 44.7 °C when placed on an 80 °C heat source. This work demonstrates that a well-engineered asymmetric structural design enables the integration of absorption-dominated EMI shielding and superior IR stealth performance within a single lightweight aerogel.