Dielectric capacitors, serving as the indispensable components in advanced high-power energy storage devices, have attracted ever increasing attention with the rapid development of science and technology. Among various dielectric capacitors, ceramic capacitors with perovskite structure show unique advantages in actual application, such as excellent adaptability in high temperature environments. And the optimization of their energy storage performances has become a hot research topic recently. This review presents the basic principles of energy storage in dielectric ceramics and introduces multi-scale synergic optimization strategies according to the key factors for superior energy storage performance. By summarizing the common points in numerous works, several universal modification strategies are reviewed and future research on fatigue fracture of ceramic capacitors under multi-field including but not limited to force, electric and thermal coupling conditions is also anticipated.

Electrostatic dielectric capacitors with ultrahigh power densities are sought after for advanced electronic and electrical systems owing to their ultrafast charge-discharge capability. However, low energy density resulting from low breakdown strength and suppressed polarization still remains a daunting challenge for practical applications. We propose a microstructural strategy with dendritic nanopolar (DNP) regions self-assembled into an insulator, which simultaneously enhances breakdown strength and high-field polarizability and minimizes energy loss and thus markedly improves energy storage performance and stability. For illustration, in this study, we achieved a high energy density of 215.8 joules per cubic centimeter with an efficiency of 80.7% at a high electric field of 7.4 megavolts per centimeter in a DNP structure–designed PbZr _0.53 Ti _0.47 O ₃ -MgO film. The proposed strategy is generally applicable for development of high-performance dielectric microcapacitors.

The synergistic contributions of high P_max, small P_r and large E_b endow the BiFeO₃-based ceramics with relaxor ferroelectric characteristics, due to which an ultrahigh W_rec of 13.9 J cm⁻³ and high η of 89.6% have been achieved synchronously.