Multifunctional lead-free piezoelectric (Ba,Ca)(Zr,Ti)O3 compounds: From energy harvesting to electrocaloric cooling and energy storage applications

Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 emerged as one of the most technologically important lead-free piezoelectric compositions, and has undoubtedly shown remarkable advancements with regards to applied research. This article outlines the technological relevance of the Ba(Zr,Ti)O3-(Ba,Ca)TiO3 based piezoelectric system, and summarizes the developments made in various traditional and emerging potential application areas. The outstanding piezoelectric properties with d33 ∼600 pC/N in BZT-50BCT laid the foundations for its applicability in mechanical energy harvesters. In recent years, its utility in energy storage and electrocaloric cooling applications have propelled its prominence in addressing the challenges associated with sustainable energy solutions. Strikingly, the characteristic ability to autonomously generate electric surface potentials with low cytotoxicity also renders the BCZT system a promising candidate for biomedical applications. Other applications explored include magnetoelectrics, photoluminescence and photocatalysis. Lastly, the future perspectives of the BCZT system are outlined based on the current research status and the existing scientific challenges.