Temperature stability of perovskite-structured lead-free piezoceramics: Evaluation methods, improvement strategies, and future perspectives

Due to ever-increasing environmental concerns, lead-free piezoceramics have been studied for more than half a century with the purpose of replacing toxic lead-based counterparts. A series of notable breakthroughs have been reported in perovskite-structured lead-free piezoceramics, such as ultra-high piezoelectric and strain properties. By contrast, the development of the temperature stability of lead-free piezoceramics has left far behind and has always been the one of the biggest hindrances for practical applications. In this context, we have summarized the most cutting-edge advances in the temperature stability of perovskite-structured lead-free piezoceramics. We first emphasized the measurement methods of evaluating temperature stability, then summarized the regulating strategies (including phase boundary engineering, texturing, composite ceramics, defect engineering, quenching, and others) used for improving the temperature stability of these lead-free piezoceramics, and addressed the physical mechanisms from a multi-scale view. Finally, we concluded advantages and disadvantages of these strategies and provided our perspective on the challenges and future research of the temperature stability. We hope that this timely review could help the development of the temperature stability of lead-free piezoceramics towards practical applications.