Hierarchical structural engineering of PEEK composites for compatible electromagnetic wave absorption and infrared stealth

The development of multifunctional materials integrating efficient electromagnetic wave attenuation with infrared signature management has become essential for next-generation defense platforms. Here, a cactus-like multifunctional stealth filler, RGO/CoZnNi@MWCNTs/VO 2 , was rationally designed and synthesized via in situ growth, controlled pyrolysis, and solvothermal processes, and subsequently incorporated into a PEEK matrix to fabricate radar–infrared compatible stealth composites. Through structural and compositional optimization, the intrinsic conflict between electromagnetic wave absorption and infrared signature suppression was effectively resolved. At a filler loading of 15 wt%, the composite delivers a minimum reflection loss of −52.80 dB with a maximum effective absorption bandwidth of 8.0 GHz. CST simulations reveal a pronounced RCS reduction of 33.64 dB m 2 when coated on a PEC substrate, corresponding to an ∼80% reduction in radar detection distance. The composite exhibits excellent infrared thermal camouflage performance, benefiting from the suppressed heat transfer from the heat source to the outer surface enabled by the low through-plane thermal conductivity (0.161 W m −1  K −1 ) and the reduced surface infrared radiation output arising from the relatively low infrared emissivity (0.60–0.63). This work provides a promising material platform for integrated radar–infrared stealth and multispectral camouflage applications.