The rapid development of electronic communication equipment, accompanied by serious electromagnetic interference problems, often leads to system instability and even equipment damage. Electromagnetic wave pollution and even contact with the human body affect our health. To reduce these risks, the development of ultra-light and flexible electromagnetic shielding materials is essential. Generally, the electromagnetic shielding performance of a material is mainly affected by its intrinsic conductivity, so highly conductive metal materials have become the most commercialized shielding materials. However, metal materials have problems such as high density, easy corrosion and inherent rigidity, which greatly limit their practical applications.
Because carbon nanomaterials have the advantages of high flexibility, ultra-high conductivity, and chemical inertness, they have important application potential in electromagnetic protection and other fields. Among them, the conductivity of two-dimensional graphene is the most excellent, which can reach 108 S/m, which has attracted widespread attention. However, there is a strong electronic coupling effect between graphene sheets in the macro-assembled graphene film, resulting in a conductivity of only ~106 S/m. At present, the use of chemical doping to increase the carrier concentration of macroscopic graphene materials and suppress the interlayer coupling effect has become a common strategy. This group has reported that the intercalation of molybdenum chloride (MoCl5) graphene film can significantly increase its conductivity to 1.73×107 S/m, and achieve stable performance in the air. However, in high-temperature environments, MoCl5 dopants are also easily removed from the graphene layers, resulting in a serious decrease in the conductivity of the graphene intercalation film, which limits its electromagnetic shielding application in many extreme environments.