High-temperature flexible electric Piezo/pyroelectric bifunctional sensor with excellent output performance based on thermal-cyclized electrospun PAN/Zn(Ac)2 nanofiber mat

High-temperature sensors are critical in petrochemical, aerospace, and automotive industries. However, the inorganic piezoelectric materials for high-temperature sensors are usually rigid and only can work in low temperatures due to their low Curie temperature (< 200 °C), which restricts these sensors for high-temperature application. Herein, we report a high-temperature piezoelectric sensor based on PAN/Zn(Ac)2 composite nanofiber mat created via electrospinning and thermal-oxidative stabilization process, which can continuously work over 500 °C. Moreover, the heat-treatment PAN is first found to be pyroelectric. The effects of the different heat-treatment temperatures on the mechanical and electrical performance of PAN/Zn(Ac)2 composite nanofiber mats are studied systematically. The maximum voltage output of the PAN/Zn(Ac)2 composite film sensor is 14.13 V at room temperature, and the voltage output of the composite film (450 ℃ heat-treated) sensor is about 14.86 V at high temperature. Besides, it has durability for over 10000 cycles (room temperature), and it has durability for over 5000 cycles and stability after 60 days (400 ℃). The PAN/Zn(Ac)2 composite nanofiber film also showed a linear voltage response to the thermal gradient, but the pyroelectric output of the PAN/Zn(Ac)2 composite nanofiber film is independent of the heat treatment temperature. The PAN/Zn(Ac)2 composite film sensor can charge a capacitor and can instantly drive small electronic devices when the capacitor discharges, and the PAN/Zn(Ac)2 composite film sensor can be applied to fire safety. Overall, good flexibility, high-temperature resistance, and bifunctional sensing ability make PAN/Zn(Ac)2-type sensors expected to be widely used in the high-temperature field of fire safety, the automotive industry, and other harsh environment.