Lead-Free Piezoceramics for Energy Transducers

Abstract

Piezoelectric materials play a vital role in modern energy transducers, sensors, actuators, and energy harvesting devices. For several decades, lead-based piezoceramics, especially lead zirconate titanate (PZT), have dominated the market due to their excellent piezoelectric and electromechanical properties. However, the toxicity of lead and strict environmental regulations have motivated extensive research toward the development of lead-free piezoceramics. In recent years, lead-free alternatives such as barium titanate (BaTiO?), potassium sodium niobate (KNN), sodium bismuth titanate (NBT), and their solid solutions have shown promising performance for energy transducer applications. This paper presents a comprehensive review of leadfree piezoceramics, focusing on their material chemistry, fabrication routes, structure–property relationships, and suitability for energy transducers. Key challenges such as low piezoelectric coefficients, temperature instability, and processing difficulties are discussed. Recent advancements including compositional modification, grain engineering, and domain wall control are highlighted. The paper also summarizes the performance of lead-free piezoceramics in vibration energy harvesting, ultrasonic transducers, and wearable energy devices. Although lead-free materials still lag behind PZT in some aspects, continuous progress indicates strong potential for sustainable and environmentally friendly energy transducer technologies.

KEYWORDS: Lead-free piezoceramics, Energy transducers, Piezoelectric energy harvesting, Barium titanate, Potassium sodium niobate