Scalable and low-cost fabrication of highly oriented ultra-thin GA pressed films for 100% EMI shielding protection

Abstract

The achievement of ∼100% electromagnetic interference (EMI) full shielding protection for military systems, pregnant women, and electromagnetic hypersensitive populations is urgently needed but still faces huge challenges. In this study, we developed a unique technical route for preparing ultra-thin and flexible graphene aggregate (GA)-pressed films with high orientation, which is realized by constructing GA-oriented aligned foams and then simply pressing the GA foams in one direction. Benefiting from its high orientation (Herman's orientation factors, f = 0.94) and remarkable compactness (a porosity of 9.8%), the 42.5 μm-thick GA pressed film exhibits an exceptionally high conductivity of 4.072 × 10⁵ S m⁻¹ and outstanding flexibility (no variation in conductivity after 100 bends). More interestingly, this ultra-thin GA pressed film exhibits an EMI shielding effectiveness (EMI SE) of up to 102 dB in the X-band, which is significantly higher than those of other films of comparable thickness reported in recent years, suggesting that the ultra-thin GA pressed film has great potential for application in fields where 100% EMI full shielding protection is required.