Enhanced energy storage in high-entropy superparaelectrics via local ferroelectric polarization

Abstract

Abstract Dielectric ceramic capacitors with ultrahigh power density have become essential in modern power electronics. Guided by phase-field simulations and experiments, we propose a “local ferroelectric–global superparaelectric” strategy. This approach enhances P m by introducing local ferroelectric polarization within a superparaelectric matrix, enabling superior energy storage performance. Introducing strong ferroelectric PbTiO₃ into a (Bi 0.2 Na 0.2 K 0.2 La 0.2 Sr 0.2 )Ti 0.9 Zr 0.1 O 3 high-entropy superparaelectric achieves an ultrahigh energy storage density of ~21 J/cm³ with an efficiency of ~87% at 110 kV/mm. Multiscale structural characterization and theoretical calculations reveal the atomic-scale mechanism for this performance enhancement. At ≤ 30% PbTiO 3 , the Pb 2+ lone pair effect is locally confined, boosting local ferroelectric distortion while maintaining a superparaelectric average structure for superior energy storage. At 40-50%, this effect extends throughout the matrix, inducing submicro-scale domains and macroscopic piezoelectricity. This work presents a design and material system for high-performance energy storage ceramics, laying the theoretical foundation for advanced high-entropy ferroelectric applications.