Heterostructured composite foam with highly efficient absorption-dominant EMI shielding capability and mechanical robustness

Highly efficient electromagnetic interference (EMI) shielding materials with strong electromagnetic (EM) waves absorption capability have attracted great interest in both academia and industry. Here, a robust heterostructured composite foam, which features both excellent EMI shielding performance and ultra-high EM waves absorption ability, is designed and fabricated, by combing an EM wave-absorbing aerogel layer with an EM wave-reflecting layer of highly conductive segregated structure. The designed heterostructure endows the composite foam with a strong interfacial dielectric loss as well as a unique “absorption-reflection-reabsorption” process towards the incident EM waves, resulting in remarkable EM waves absorption capability with a power coefficient of reflectivity as low as 0.16 and a high EMI SE. Furthermore, the engineered composite foam demonstrates desirable flexibility and superior robustness towards mechanical damages. This work provides a simple and effective strategy for the preparation of ultra-robust, highly efficient, and absorption-dominated EMI shielding materials.