Optimization of properties in barium titanate-based ceramics via defect chemistry

• Reviews defect chemistry strategies for tuning the dielectric, ferroelectric, and energy storage properties of BTO-based ceramics. • Summarizes the effects of A-site, B-site, and co-doping on crystal structure, phase transitions, and microstructure. • Discusses the role of point defects, oxygen vacancies, and dopant-induced lattice distortions in controlling polarization and dielectric loss. • Identifies challenges and future directions for designing high-performance BTO ceramics via precise defect engineering. With the rapid development of electronic components and energy storage devices, obtaining barium titanate (BaTiO 3 , BTO)-based ceramics with high dielectric performance and reliable stability has become an important research topic. As a representative perovskite-type ferroelectric ceramic, BTO has attracted extensive attention because of its excellent dielectric, piezoelectric, and pyroelectric properties. However, its practical application is often limited by intrinsic defects and doping-induced defects, which strongly affect dielectric response, insulation characteristics, and performance stability. In recent years, defect chemistry has gradually become an important theoretical framework for understanding and regulating the relationship between microstructure and macroscopic properties in BTO-based ceramics. This review systematically summarizes the performance optimization of BTO from the perspective of defect chemistry. The importance of the perovskite structure and the fundamental characteristics of BTO are first outlined, followed by a discussion of the basic principles of defect chemistry and their application value in functional ceramics. Particular emphasis is placed on recent advances achieved through Ba-site doping, Ti-site doping, dual-site co-doping, and other emerging doping strategies. Finally, current research limitations and future perspectives are summarized.