Highly flexible and ultra-thin Ni-plated carbon-fabric/polycarbonate film for enhanced electromagnetic interference shielding

Abstract We report in this work a highly flexible, mechanically robust, and ultra-thin Ni-plated nonwoven carbon fabric/polycarbonate (CF/PC/Ni) film that exhibits outstanding electromagnetic interface (EMI) shielding performance. This composite film is fabricated through a four-step process — fabrication of nonwoven carbon fiber/polypropylene/polyethylene (CEF-NF) fabric, catalytic seeding and sensitization, electroless Ni plating, and lamination with polycarbonate. The as-fabricated ultra-thin (0.31 mm) CF/PC/Ni film exhibits superior EMI shielding effectiveness (EMI-SE) of 72.7 dB, which is close to 3× that of an identical film with no Ni plating (25 dB)—demonstrating Ni plating can substantially improve the EMI shielding performance. Compared with similar lightweight EMI-shielding materials, this CF/PC/Ni film shows a superior EMI-SE at lower density and smaller thickness (1376.1 dB cm2 g−1). 40 min of Ni plating (yielding a Ni thickness of 1.075 μm), followed by 2 MPa of laminating pressure at 190 °C of laminating temperature were found to provide optimal EMI shielding performance. Based on reliability study, the CF/PC/Ni film retains 96.36% of its EMI-SE after 5000 cycles of mechanical bending and 50 h of heating. Therefore, the CF/PC/Ni film exhibits outstanding flexibility, good mechanical strength, and remarkable electrical properties, making it an excellent EMI shielding material.