Performance Optimization of Pyroelectric Energy Conversion Device upon Phase Transformation

Abstract

Waste heat in industrial scenarios and the daily environment accounts for a large portion of unutilized energy. Converting low-grade temperature oscillations into electrical energy based on the pyroelectric effect is a promising method. Recent progress has been made in enhancing energy conversion performance through material development, and an innovative power-source-free characterization method has been introduced to clearly attribute the converted electricity to temperature fluctuations. Yet, little is explored about the performance optimization and the operation parameters of the device upon phase-transforming energy conversion. Demonstrations of pyroelectric energy conversion directly using heating and cooling benches, however, usually confront problems of portability, and the difficulties of regulating the temperature oscillation frequency and rate.

To tackle these existing drawbacks, an operable BaTiO₃ based pyroelectric energy conversion device that can generate tunable temperature fluctuation close to natural conditions is investigated and optimized. The device’s performance illustrates the significant potential of the pyroelectric phase transition energy harvesting, particularly in terms of its energy output profile. Specifically, by conducting benchmark experiments through tuning a single operation parameter in each set of testing, we explore the impact of the non-material operating parameter on the output pyroelectric energy performance innovatively. Moreover, we also derive the material efficiency of pyroelectric energy conversion and analyze the practical device efficiency to measure the effectiveness and feasibility. Finally, we propose an integrated energy conversion device that can adapt to different phase-transforming capacitors and generate adjustable temperature fluctuations without any external power source. Moreover, the effect of operation parameters for device optimization is unveiled, and the energy conversion efficiency is derived to clarify the confusion and contribute to the promising waste heat energy harvesting.

Date of Award	2025
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology
Supervisor	Sherry CHEN (Supervisor)