Multifunctional NiSe2/C/PI aerogel: Packing design of ultra-light electromagnetic wave absorbers with excellent heat and pressure resistance

The inherent conflict between lightweight design and mechanical performance in electromagnetic wave (EMW) absorption materials poses a significant challenge. In this study, we propose a promising strategy involving polyimide (PI) aerogels functionalized with NiSe₂/CNT and NiSe₂/GN as dual-phase fillers. The synergistic effects of carbon frameworks and NiSe₂ significantly enhance the mechanical robustness and thermal stability of the composites while retaining ultralow density. Experimental results show that the aerogels with multifunctional fillers achieve breakthrough performance. Specifically, the NiSe₂/CNT/PI aerogel exhibit a compressive strength of 1929.69 kPa and maintained a temperature differential exceeding 100 °C under 150 °C heating, demonstrating exceptional thermal insulation. Furthermore, this aerogel delivers a minimum reflection loss of −42.25 dB with an effective absorption bandwidth of 2.06 GHz at an ultra-thin thickness of 1.57 mm, surpassing most reported broadband absorbers. This study successfully resolves the mechanical-lightweight conflict, thus providing actionable insights for designing advanced multifunctional EMW absorbers.