MXene‐Driven Metacomposites With Low‐Dispersion Negative Permittivity and Epsilon‐Near‐Zero Properties

Metacomposite development faces significant challenges in achieving epsilon‐near‐zero (ENZ) permittivity within radio frequencies while overcoming severe dispersion limitations. To address this, Ti ₃ C ₂ T _x MXene/polyimide nanocomposites were fabricated through mechanical mixing and pressure molding. By varying MXene content, a 3D conductive network was engineered, achieving electrical percolation. Below the threshold, dielectric behavior followed Debye relaxation, while above it, negative permittivity exhibited Drude‐type dispersion. Notably, near the percolation threshold (∼78 vol%), ENZ properties emerged at 501 MHz with a unique Debye–Drude coexistence. Equivalent circuit analysis revealed a capacitive‐to‐inductive transition, further elucidating the low‐dispersion behavior. This study introduces a novel Debye–Drude copolarization model, providing a theoretical framework for designing low‐dispersion negative permittivity materials with broad electromagnetic applications.