Fabricating flexible and large-scale graphene-based films through a simple process to achieve excellent electromagnetic interference (EMI) shielding performance is still a daunting challenge. Herein, the flexible and large-area EMI shielding films with ultrathin coating thickness (i.e., 10 μm) and low coating density (i.e., 2.4 mg/cm²) were fabricated through a simple drop-casting approach by using graphene-based conductive ink at room temperature. With the aid of electromagnetic simulation, the optimal square resistance of conductive film for desirable EMI shielding effectiveness is predicted, avoiding the unnecessary costs of error and trial. To solve the vital issue of poor conductivity of reduced graphene oxide (RGO) arising from defects and the serious agglomeration of each filler in ink, a three-dimensional network was constructed by connecting RGO with flexible one-dimensional (1D) conductive fibers (i.e., carbon nanotubes (CNT) and Ag nanowire (AgNW)). The square resistance of the RGO/CNT@Epoxy/AgNW composite film could reach as low as 1.94 ± 0.63 Ω/sq, which exhibited the shielding effectiveness value of 40 dB at a minimum in 8.2–12.5 GHz. These attributes could satisfy the EMI shielding and flexibly conformal demands of most communication equipment.

通过简单的工艺来制造柔性且大规模的石墨烯基薄膜以实现出色的电磁干扰（EMI）屏蔽性能仍然是一项艰巨的挑战。在此，具有超薄涂层厚度（即10μm）和低涂层密度（即2.4 mg / cm ²）的柔性大面积EMI屏蔽膜）是在室温下使用石墨烯基导电油墨通过简单的滴铸法制造的。借助电磁仿真，可以预测出具有理想的EMI屏蔽效果的最佳导电膜平方电阻，从而避免了不必要的错误和试验成本。为了解决因缺陷而导致还原型氧化石墨烯（RGO）的导电性差以及墨水中每种填料严重团聚的重要问题，通过将RGO与柔性一维（1D）导电纤维（即，碳纳米管（CNT）和银纳米线（AgNW））。RGO / CNT @环氧树脂/ AgNW复合膜的平方电阻可低至1.94±0.63Ω/ sq，在8.2–12.5 GHz范围内显示出至少40 dB的屏蔽效果。这些属性可以满足大多数通信设备的EMI屏蔽和灵活的共形要求。