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 structures show unique advantages in actual application, e.g., excellent adaptability in high-temperature environments. And the optimization of their energy storage performance 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.

The development of environmentally friendly ceramics for electrostatic energy storage has drawn growing interest due to the wide application in high power and/or pulsed power electronic systems. However, it is difficult to simultaneously achieve ultrahigh recoverable energy storage density (W_rec > 8 J/cm³) and high efficiency (η > 80 %), which restricts their application in the miniaturized, light weight and easy integrated electronic devices. Herein, the novel NaNbO₃-(Bi_0.8Sr_0.2)(Fe_0.9Nb_0.1)O₃ relaxor antiferroelectric ceramics, which integrates the merits of antiferroelectrics and relaxors, are demonstrated to exhibit stabilized antiferroelectric phase and enhanced dielectric relaxor behavior. Of particular importance is that the 0.88NN-0.12BSFN ceramic achieves giant electric breakdown strength E_b = 98.3 kV/mm, ultrahigh W_rec = 16.5 J/cm³ and high η = 83.3 %, as well as excellent frequency, cycling and thermal reliability simultaneously. The comprehensive energy storage performance of NN-BSFN not only outperforms state-of-the-art dielectric ceramics by comparison, but also displays outstanding potential for next-generation energy storage capacitors.