Design strategies of high‐performance lead‐free electroceramics for energy storage applications

Abstract A greater number of compact and reliable electrostatic capacitors are in demand due to the Internet of Things boom and rapidly growing complex and integrated electronic systems, continuously promoting the development of high‐energy‐density ceramic‐based capacitors. Although significant successes have been achieved in obtaining high energy densities in lead‐based ferroelectric ceramics, the utilization of lead‐containing ceramics has been restricted due to environmental and health hazards of lead. Lead‐free ferroelectric ceramics have garnered tremendous attention and are expected to replace lead‐based ceramics in the near future. However, the energy density of lead‐free ceramics is still lagging behind that of lead‐containing counterparts, severely limiting their applications. Significant efforts have been made to enhance the energy storage performance of lead‐free ceramics using multi‐scale design strategies, and exciting progress has been achieved in the past decade. This review briefly discusses the energy storage mechanism and fundamental characteristics of a dielectric capacitor, summarizes and compares the state‐of‐the‐art design strategies for high‐energy‐density lead‐free ceramics, and highlights several critical issues and requirements for industrial production. The prospects and challenges of lead‐free ceramics for energy storage applications are also discussed.