Porous Pyroelectric Ceramic with Carbon Nanotubes for High-Performance Thermal to Electrical Energy Conversion

Abstract

The recycling of low-grade thermal energy from our surroundings is an environmental-friendly approach to contribute to sustainability, which remains a grand challenge. Herein, a high-performance porous pyroelectric ceramic formed using carbon nanotubes (CNT) is designed and fabricated using a modified solid-state reaction technique. Local characterization by piezoelectric force microscopy suggests that the presence of porosity and defects in grains can restrict the reversal of domains and weaken the local piezoresponse under an electric field. The piezoresponse amplitudes of PMN-PMS-PZT and PMN-PMS-PZT with 0.3 wt.% CNT additions showed that the presence of porosity can influence domain reversal and the local piezoresponse due to influence of pores on the electric field and domain morphology, or screening effects of defect on pore surface. More importantly, the porous ceramics showed enhanced figure of merits, including voltage responsibility and energy harvesting figure of merit, compared to the dense ceramic. The harvested energy increased by 208% when the 0.3 wt.% of CNT was added to produce porosity, which has a potential application in thermal energy harvesting and sensing system.

Keywords: Pyroelectricity, Porous pyroelectric ceramic, PFM, CNT, FOMs, Thermal energy harvesting