Recycled Piezoelectric Materials with Competitive Second‐Life Functional Properties

ABSTRACT EU laws restrict the use of hazardous elements in electrical and electronic equipment and encourage their recycling. However, lead is currently exempted from this restriction due to its indispensable role in essential piezoelectric materials. Here, we tackle this problem by demonstrating the feasibility of recycling lead‐containing piezoelectric ceramics and giving them a second life, so that disposal of lead into the environment can be avoided or postponed. By exploring the use of a high‐permittivity polymer binder in this work, we are able to achieve optimum piezoelectric properties among all known recycled materials by consuming only negligible energy compared to that needed for producing new materials. We also provide insights into the roadmap for further developing the recycling method by mapping the correlations between decisive factors. After recycling, this work achieved 40% and 100% retention of piezoelectric charge and voltage coefficient values, respectively, compared to the pristine products prior to recycling, indicating superior properties of the recycled materials that can be given a second life in sensing and actuating components.