Multifunctional Liquid Metal‐Bridged Graphite Nanoplatelets/Aramid Nanofiber Film for Thermal Management

Miniaturization of modern micro‐electronic devices urges the development of multi‐functional thermal management materials. Traditional polymer composite‐based thermal management materials are promising candidates, but they suffer from single functionality, high cost, and low fire‐resistance. Herein, a multifunctional liquid metal (LM)‐bridged graphite nanoplatelets (GNPs)/ aramid nanofibers (ANFs) film is fabricated via a facile vacuum‐assisted self‐assembly approach followed by compression. ANFs serve as interfacial binders to link LM and GNPs together via hydrogen bondings and π–π interactions, while LM bridges the adjacent layer of GNPs to endow a fast thermal transport by phonons and electrons. The resultant composite films exhibit a high bidirectional thermal conductivity (In‐plane: 29.5 W m−1K−1 and through‐plane: 5.3 W m−1K−1), offering a reliable and effective cooling. Moreover, the as‐fabricated composite films exhibit superior flame‐retardance (peak of heat release rate of 4000J g−1), outstanding Joule heating performance (200 °C at supplied voltage of 3.5 V), and excellent electromagnetic interference shielding effectiveness (EMI SE of 62 dB). This work provides an efficient avenue to fabricate multifuntional thermal management materials for micro‐electronic devices, battery thermal management, and artificial intelligence. A multi‐functional liquid metal‐bridged graphite nanoplatelets/aramid nanofiber film is proposed to be functioned as, thermal conductive materials, flame retardant layer, flexible Joule heater, and electromagnetic shielding layer.