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

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 EA simultaneously, while maintaining a stable forward switching field EF. An ultrahigh energy density of 50 J cm−3 is achieved for the nominal Pb0.925La0.05ZrO3 (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.