Negative Dielectric Properties and Percolation Behavior of Graphite Sheet/PVDF Composites

Negative dielectric materials exhibit tremendous application potential in areas such as electromagnetic wave manipulation and metamaterial design. This article focuses on graphite sheet/polyvinylidene fluoride (PVDF) composites, systematically investigating their negative permittivity and percolation behavior. It is observed that an increase in graphite sheet content leads to the establishment of a conductive network within the composite, resulting in a percolation phenomenon with a percolation threshold of ≈16 wt%. Notably, when the graphite sheet content reaches 30%, the composite exhibits a near‐zero dielectric state at high frequencies, with its dielectric behavior conforming to the Debye–Drude model. Hopping conduction and metal‐like conduction dominate the conductive mechanism of the composite, and percolation behavior plays a pivotal role in the formation of negative permittivity. Additionally, reactance is analyzed based on equivalent circuit analysis, and the electromagnetic shielding performance of the composite is also studied, achieving a maximum of 40 dB in the X ‐band range with a thickness of 0.33 mm. This work is cost‐effective and straightforward, providing experimental evidence for a deeper understanding of the intrinsic relationship between negative‐dielectric properties and percolation behavior, and is expected to drive the advancement of negative‐dielectric materials in fields such as metamaterial design.