Polymorphic Polar Ordering Engineered Relaxor Antiferroelectric for High Energy Storage Performance

Antiferroelectrics are promising for high-energy-density storage owing to their characteristic double hysteresis loops. However, their performance is severely limited by their antiferroelectricity instability, low breakdown strength, and high hysteretic loss. This study proposes a performance optimization strategy based on polymorphic polar order engineering. By the introduction of LaScO 3 nonpolar end-member into antiferroelectric PbHfO 3 , the long-range antipolar orders were disrupted and thus establish a polymorphic polar configuration, combining short-range antipolar orders and disordered nonpolar regions. This structure, directly observed via atomic-scale scanning transmission electron microscopy, simultaneously delays the antiferroelectric-ferroelectric phase transition field, depresses the field-induced hysteretic loss, and improves the breakdown field. Consequently, the optimized polymorphic PbHfO 3 −based relaxor antiferroelectric achieves a high energy density of 100.3 J cm − 3 and efficiency of 76.3%, rivaling the advanced antiferroelectrics. Moreover, the films demonstrate exceptional stability under a broad temperature (−100°C to 200°C) and frequency (1–100 kHz) ranges, as well as extended cycling (up to 10 8 cycles). This work not only elucidates the microscopic mechanism of polymorphic polar order in optimizing antiferroelectric energy storage performance but also provides a novel design strategy for antiferroelectrics that integrates high energy density, high efficiency, and superior reliability.