Min Su Kim, Bo‐Kyung Choi, Ki Hoon Kim, Ji‐Hun Kang, Chaewook Jo, Jong‐Hyun Park, Seong Yun Kim
ABSTRACT As electronic devices and components continue to become more powerful and highly integrated, there is an increasing demand for lightweight, cost‐effective, and easy‐to‐process conductive materials. In this study, we fabricate a hybrid composite based on metal‐coated carbon fibers (MCFs) and multi‐walled carbon nanotubes (MWCNTs) that exhibits improved electrical and mechanical properties. MCFs are effective in simultaneously improving the electrical and mechanical properties of the composites, and incorporating additional MWCNTs could further enhance these properties while reducing the amount of expensive MCF required. To ensure uniform filler dispersion and establish an ideal hybrid network, MCFs and MWCNTs were processed as long‐fiber thermoplastics and a masterbatch, respectively. MWCNTs acted as electrical bridges within the hybrid composites, contributing to enhanced electrical conductivity. However, excessive MWCNT loading resulted in poor MCF dispersion and delamination of the metal layer. Consequently, optimizing the MCF to MWCNT ratio was essential. The optimized MCF 5 wt% and MWCNT 5 wt% hybrid composite achieved electromagnetic shielding effectiveness of 72.1 dB, electrothermal conversion of 115°C, and tensile strength of 71.6 MPa. These results demonstrate a scalable MCF/MWCNT hybrid composite system with excellent electrical, electrothermal, and mechanical performance.