Ultrahigh Energy Density of Antiferroelectric PbZrO₃‐Based Films at Low Electric Field

Abstract Dielectric capacitors play a vital role in advanced electronics and power systems as a medium of energy storage and conversion. Achieving ultrahigh energy density at low electric field/voltage, however, remains a challenge for insulating dielectric materials. Taking advantage of the phase transition in antiferroelectric (AFE) film PbZrO₃ (PZO), a small amount of isovalent (Sr²⁺) / aliovalent (La³⁺) dopants are introduced to form a hierarchical domain structure to increase the polarization and enhance the backward switching field E_A simultaneously, while maintaining a stable forward switching field E_F. An ultrahigh energy density of 50 J cm⁻³ is achieved for the nominal Pb_0.925La_0.05ZrO₃ (PLZ5) films at low electric fields of 1 MV cm⁻¹, exceeding the current dielectric energy storage films at similar electric field. This study opens a new avenue to enhance energy density of AFE materials at low field/voltage based on a gradient‐relaxor AFE strategy, which has significant implications for the development of new dielectric materials that can operate at low field/voltage while still delivering high energy density.