Foam-structured carbon materials and composites for electromagnetic interference shielding: Design principles and structural evolution

Electromagnetic interference (EMI) shielding materials have received numerous attention over the past decades, because of the explosive growth of EMI issues and electromagnetic pollution. Owing to their fascinating characteristics such as lightweight, high mechanical strength, anti-corrosion, and good chemical stability, foam-structured carbon materials exhibit great potential in EMI shielding and receive increasing attention in the past few years. Herein, we provide a comprehensive review of recent advances in the design of foam-structured carbon materials for EMI shielding applications. First, the various synthesis approaches for foam-structured carbon materials are outlined, including 3D printing, rapid solvent evaporation, supercritical foaming process, carbonization method, etc. Then, the EMI shielding properties of different foam-structured carbon materials are summarized, including graphene foam, carbon nanotubes (CNTs) foam, polymer-based carbon foam, pitch-based carbon foam, and biomass-based carbon foam. Last, the existing challenges and possible solutions in the field are discussed. Moreover, the prospectives of the foam-structured carbon materials for EMI shielding applications are discussed. This review will shed light on the fundamental understanding of foam-structured carbon materials used for EMI shielding and will inspire further research on EMI shielding issues that could be addressed by foam-structured carbon materials.