Molecular‐Scale Carrier Localization Boosts High‐Temperature Energy Storage and High‐Entropy Energy Harvesting

Abstract High‐temperature insulation/energy storage applications boost the rapid development of polymer dielectrics such as polyimide (PI) with excellent thermal stability. However, PI exhibits significant leakage current due to intra‐ and inter‐chain charge transfer complexes (CTCs), which seriously increases the risk of thermal runaway. Although single charge transfer inhibition strategies have been developed, the results remain unsatisfying due to the “short‐board effect in carrier suppression.” Herein, a “carrier localization” approach is introduced that synergistically regulates both intramolecular and intermolecular CT suppression. Thanks to molecular engineering and a directional intercalation structure, the all‐organic polyimide dielectric materials with multidimensional carrier migration suppression achieve an exceptional breakdown strength of 878.9 kV mm −1 and U d of 8.93 J cm −3 at 150 °C and energy density of 5.64 J cm −3 at 200 °C ( η > 90%), outperforming many reported systems. The all‐organic polyimide dielectric materials also enable to possess high charge density (215 µC m −2 ) when integrated into a self‐excited triboelectric nanogenerator, which is highly desirable for the harvesting of low‐frequency, irregular mechanical energy from a high‐entropy environment. Collectively, this work provides a solid foundation for advanced energy storage and conversion applications.