Graphene Film Rolls With Superior Thermal Conductivity and Electromagnetic Interference Shielding Capabilities

ABSTRACT Despite graphene's ultrahigh in‐plane thermal conductivity ( κ ∼5300 W·m − 1 ·K − 1 ), thick graphene films typically suffer from drastically reduced κ (<1300 W·m − 1 ·K − 1 ) due to interlayer phonon coupling and defect scattering, underperforming commercial pyrolytic graphite sheets (PGS). Furthermore, pyrolysis‐induced interlayer voids degrade mechanical integrity and interlayer connectivity. We introduce an industrial‐scale manufacturing platform that synergistically integrates controlled coating, thermal annealing, in situ vacuum degassing, and roll‐to‐roll mechanical pressing, to produce void‐free graphene film rolls (GFRs, 19–211 µm thick). Graphitization of graphene oxide paste coating, prepared from agitated precursor dispersions, promotes disordered turbostratic stacking (∼15.21%), weakening interlayer coupling and suppressing phonon scattering. Subsequent degassing and pressing establish near‐perfect in‐plane alignment with an ideal interlayer spacing (∼3.37 Å), significantly enhancing thermal and electrical connectivity. The resulting GFRs achieve κ rivaling PGS (∼1634 W·m − 1 ·K − 1 ), while exhibiting multifunctional superiority, including exceptional flexibility, high electrical conductivity (9168 S/cm), and outstanding electromagnetic interference shielding (32 dB at 8.2 GHz). This performance is further enabled by large lateral sheet sizes and extensive crystallite domains. The combination of high κ and substantial thickness allows rapid heat spreading, achieving thermal equilibrium within seconds, 10 times faster than prior studies, representing a significant advancement in scalable graphene‐based thermal management and electromagnetic shielding applications.