Efficient preparation of large-area anisotropic graphite films with high thermal conductivity and excellent electromagnetic shielding performance

High power consumption and operating frequencies of advanced electronic devices result in significant heat generation and a complex electromagnetic environment. This creates an urgent need for materials that cover large areas, have high thermal conductivity, and offer strong electromagnetic compatibility. In this work, large-area graphite films with high thermal conductivity and excellent electromagnetic shielding properties were fabricated using glucose as a carbon source. The introduction of carboxymethyl cellulose (CMC) ensures the integrity of the film, the unidirectional shrinkage, and the template of pyrolyzed polyimide resulting in an oriented graphite structure. The graphite films exhibit in-plane thermal conductivity as high as 567 W/(m∙K), showing significant advantages in lightweight design and heat dissipation over conventional metal-based thermal management materials. The interlayer reflection structure existing in the multilayer graphite film exhibits excellent electromagnetic shielding performance, achieving an EMI shielding effectiveness of 40.79 dB in the Ku band and a shielding efficiency up to 59,399 dB·cm 2 ·g −1 with a thickness of 3 μm, significantly surpassing most reported synthetic materials. Moreover, the excellent mechanical properties further broaden the application potential of these graphite films. This research provides a renewable carbon source, pressure-free orientation and effective solution to meet the urgent demand of modern advanced electronic devices for materials with large-area, high thermal conductivity, and high electromagnetic shielding capacities.