Electrospun Polyimide Nanofiber-Based Triboelectric Nanogenerator for Harvesting Energy at Elevated Temperatures

The thermionic emission effect and the destruction of the polymer surface structure caused by elevated temperatures severely affect the electron transfer in triboelectric nanogenerator (TENGs); thus, previous studies on the performance of polymer-based TENGs at elevated temperatures have mainly focused on that below 200 °C. Polyimide (PI) with high thermal stability and excellent triboelectric negativity has been widely used in the TENG but lacks systematic investigation in high-temperature environments. Hence, we systematically evaluated the output performance of a polyimide nanofiber-based TENG (PINF-TENG) composed of an electrospun polyimide nanofiber (PINF) and copper foil at 25–250 °C. The PINF-TENG generated an open-circuit voltage of 60.83 V and a short-circuit current of 1.52 μA at 25 °C, and a peak power density of 17.36 mW/m2 was achieved on a 50 MΩ external load. The open-circuit voltage and short-circuit current decreased sharply with the increase of temperature, while the optimal load resistance increased, which has not been reported in previous studies of polymer-based TENGs. In addition, the PINF-TENG can still maintain 25.48% of the voltage and 23.03% of the current at 250 °C with regard to those at 25 °C, which can stably charge the capacitor and drive 20 commercial green light-emitting diodes (LEDs). Therefore, this PINF-TENG has great application prospects for harvesting energy and sensing motion in hot gas, space, and many other high-temperature environments.