ABSTRACT Dielectric capacitors are essential for high‐power, fast‐response electronics, but their performance is limited by trade‐offs between high polarization, low hysteresis loss, and high breakdown strength. The urgent need for eco‐friendly materials has spurred intense interest in lead‐free oxide dielectrics. Recent advances in synthesis and advanced characterization have revealed that atomic‐ and nanoscale local structures exert a profound influence on energy‐storage performance. Specifically, local polar nanoregions, chemical inhomogeneities, lattice distortions, and interfacial architectures play a pivotal role in regulating polarization configuration, leakage behavior, and breakdown pathways. This review systematically summarizes recent progress in lead‐free dielectric oxides through local structural design. After a concise overview of dielectric energy‐storage principles and classification, representative systems are discussed, with a focus on how specific local structural motifs correlate with macroscopic performance. The emerging strategies, such as local chemical framework design, high‐entropy approaches, polar nanodomain engineering, local microstructure architectures, multiphase/heterogeneous interfaces, and local amorphous design, are summarized. By integrating key advances in this field, the review clarifies intrinsic structure‐property relationships, identifies current challenges, and outlines opportunities for future breakthroughs, which could deliver timely guidance for designing high‐performance and environmentally benign dielectric capacitors.
Xie et al. (2026) studied this question.