Honeycomb-Patterned Polyimide-Based Triboelectric Nanogenerator with Excellent Thermal Stability and Enhanced Electrification Performance

In this era of the Internet of Things, the triboelectric nanogenerator (TENG) is one of the first green-energy technologies that can convert random mechanical kinetic energy into electricity for self-powered mobile electronics. Even with its strengths, such as ease of fabrication, flexibility, compactness, and high electrical output, TENG still has some weaknesses, including weak durability and low resistance to harsh conditions. These weaknesses limit the practical applications of TENG, particularly in industrial sectors. As a resolution of these issues, this paper proposes a tribo-electret, which can make amends for typical TENG imperfections on the basis of a surface-patterned high-temperature-resistant thermoplastic. The customizable honeycomb-patterned polyimide (hc-PI), fabricated by a simply scalable improved phase separation method, compensates for the aforementioned issues due to the fact that PI is an excellent heat-resistant flexible thermoplastic with ideal mechanical properties, and the dead-end pore honeycomb pattern array enables it to optimize the electrification efficiency of TENG. Our TENG device possesses an outstanding output power of 1.05 W m^-2, which is an enhancement of 22 times in comparison to that of a TENG assembled with normal flat PI. Furthermore, an excellent durability of 20000 contact-separation cycles was obtained and the perfect honeycomb patterns still remained afterward. More interestingly, our present TENG exhibited an upward trend in the output voltage at elevated temperatures, and for the first time, it was tested at a working temperature of up to 200 °C. The newly developed hc-TENG achieves a great convergence among excellent flexibility, thermostability, durability, and superior electrical output. This will greatly contribute to the development of future self-powered electronics and sensors applied in harsh environments.