Triboelectric Polymer with High Thermal Charge Stability for Harvesting Energy from 200 °C Flowing Air

Abstract Due to the thermionic emission effect, the electron transferred to dielectric surface can be released into vacuum after the contact electrification (CE). Therefore, triboelectric nanogenerator (TENG) cannot maintain effective electrical output under high temperature conditions. In order to obtain high thermal charge stability, polyimide is modified with strong electron withdrawing groups like trifluoromethyl (CF 3 ) and sulfone group (SO 2 ) in backbone. The fluorinated polyimides (F‐PI) with a big band gap can provide a tribocharge density of 170 µC m −2 (4 times of common Kapton film) and become more negative than polytetrafluoroethylene in triboelectric series. In addition, BaTiO 3 nanoparticles are doped in F‐PI film for inducing deep traps and interfacial polarizations for CE, which can further enhance the charge density (200 µC m −2 ) and thermal charge stability. Finally, a flutter‐driven TENG (FD‐TENG) is designed based on this BaTiO 3 ‐doped F‐PI film to harvest wind energy and sense wind velocity. This FD‐TENG can maintain 32% of its output performance at 200 °C in comparison with room temperature, which is the highest thermal charge stability reported for triboelectric polymers. Therefore, this BaTiO 3 ‐doped F‐PI has great application prospects for energy generation and motion detection in hot wind tunnel and many other harsh environments.