Structure-enhanced ultra-high EMI shielding in corrugated recycled carbon fiber felts

The rapid advancement of electronic information technology has led to a significant increase in electromagnetic radiation from electronic devices, posing potential threats to human health. Developing lightweight, high-performance, and green electromagnetic interference (EMI) shielding materials is crucial for mitigating electromagnetic pollution. Herein, uniformly dispersed recycled carbon fiber corrugated felt (rCCFF) was fabricated via wet-laid technology combined with structural design. Results demonstrate that the corrugated structure significantly enhances the shielding effectiveness (EMI SE). Optimal EMI SE of 46 dB was achieved when the corrugation direction was parallel (0°) to the polarization direction of the electromagnetic field, representing a 29.6 % improvement over the planar structure. Reducing the corrugation diameter to 1.2 mm enhanced multiple reflections and interfacial polarization, further increasing the EMI SE to 55.26 dB. Moreover, the double-layer stacked structure forms numerous miniature air cavities, effectively exciting multiple reflections and creating multi-scale resonant coupling, thereby achieving an excellent EMI SE of up to 68.5 dB.