Abstract
ABSTRACT Expanding the library of polarity‐engineered polymers is essential for enhancing performance and designing the flexibility of triboelectric nanogenerators (TENGs). Herein, we report a polyimide (PI) film derived from an imidazolium‐mediated cross‐linked 6FDA‐durene polymer, with bromine anions as counterions, enabling surface polarity modulation and improved charge transfer. XPS and FT‐IR analyses confirm the formation of imidazolium‐mediated crosslinks in the 6FDA‐durene polyimide, verifying the successful incorporation of ionic liquid groups into the polymer structure. Density‐functional theory (DFT) calculations reveal that imidazolium crosslinking shifts the HOMO upward by 1 eV, lowering the electron‐transfer barrier and switching the triboelectric polarity from negative to positive. The fabricated TENG achieves a power density of 85.67 mW/m 2 at 3 N and 3 Hz, lighting 81 LEDs and powering a calculator. The crosslinked material maintains stable performance over 64 800 cycles at 50°C, demonstrating thermal robustness. This polarity‐tunable, thermally stable polymer is a promising candidate for transparent TENGs in displays, windows, pavements, and hybrid energy systems.