The lead-free sodium bismuth titanate (BNT) system has been extensively investigated in the past decade due to its multi-functional electro-active properties. Here, we present a comprehensive review that encompasses the fundamentals and state-of-the-art in the development of BNT-based ceramics, with attention to the underlying composition, microstructure, and macroscopic properties. The phase structure, phase transitions, and relaxor characteristics of BNT and BNT-based solid solutions are described carefully, with a series of proposed phase diagrams. The attractive functional properties of BNT-based ceramics include piezoelectricity, electric-field-induced strain, and energy storage performance for applications in sensors, actuators, and dielectric capacitors. The focus of this review is on the microscopic origin of the macroscopic behavior, the proposed strategies for optimization of functional properties, and current challenges. Moreover, the potential applications of BNT-based ceramics in the areas of electrocaloric, oxide-ion conduction, and luminescence are briefly introduced. Finally, future perspectives are provided to highlight new and emerging research directions in this growing area.

无铅钛酸铋钠（BNT）体系由于其多功能电活性特性，在过去十年中得到了广泛的研究。在这里，我们全面回顾了 BNT 基陶瓷开发的基础知识和最新技术，并关注潜在的成分、微观结构和宏观特性。详细描述了 BNT 和基于 BNT 的固溶体的相结构、相变和弛豫特性，并提供了一系列相图。BNT 基陶瓷的吸引人的功能特性包括压电性、电场诱导应变和储能性能，可用于传感器、执行器和介电电容器。这篇综述的重点是宏观行为的微观起源，用于优化功能特性的拟议策略以及当前的挑战。此外，还简要介绍了 BNT 基陶瓷在电热、氧离子传导和发光领域的潜在应用。最后，提供了未来的观点，以突出这一不断发展的领域中新兴的研究方向。