Spatial Topology of Molecular Traps for High‐Temperature Capacitive Energy Storage

Thermally accelerated charge injection and carrier hopping intrinsically limit high‐temperature polymer dielectrics. While introducing organic semiconductor traps is a proven mitigation strategy, the influence of their spatial topology on local matrix packing and macroscopic dielectric stability remains largely unexplored. In this study, we utilize the spatial topology of polycyano arenes to construct localized molecular traps within a polyetherimide matrix. Physical characterization and theoretical calculations establish that the adjacent cyano geometry in 1,2,4,5‐tetracyanobenzene dictates a highly localized positive electrostatic distribution. This specific molecular architecture simultaneously restrains the segmental mobility of adjacent polymer chains via steric locking to systematically reduce the fractional free volume, and establishes deep energetic traps through its pronounced electron affinity. This dual mechanism of localized electrostatic confinement and deep trapping structurally and energetically restricts continuous charge transport under elevated temperatures. Consequently, the optimal composite achieves a breakdown strength of 661 MV/m and delivers a discharged energy density of 5.23 J/cm 3 with > 90% efficiency at 200°C, maintaining stable operation over 100 000 continuous cycles. Modulating the spatial topology therefore provides a reproducible structural approach for designing high‐temperature polymer capacitors.