Designing Artificial Mesoscopic‐Scale Heterolayers for Ultrahigh Energy Storage

Conventional doping approaches in antiferroelectric (AFE) ceramics inevitably involve a trade‐off between maximizing polarization ( P max ) and sustaining high breakdown strength ( E B ), which fundamentally limits energy storage performance. Here, we present a paradigm‐shifting strategy based on the deliberate design of mesoscale heterolayers integrating antiferroelectric PbHfO 3 and linear dielectric SrHfO 3 , effectively overcoming this long‐standing challenge. Guided by phase‐field simulations, we fabricate laminated ceramics with an optimally tuned fraction of the linear dielectric layer. The resulting heterostructure leverages controlled electric‐field redistribution and interfacial effects, enabling synergy between the properties of the two constituents. This synergy yields a superior recoverable energy density of 23.1 J cm −3 along with a high efficiency of 83.7%, surpassing any performance achievable through a simple rule of mixtures. This heterolayer design principle establishes a general and effective route for engineering high‐performance dielectric composites for advanced energy storage applications.