Superior Energy Storage Performance in Antiferroelectric Epitaxial Thin Films via Structural Heterogeneity and Orientation Control

Abstract

Dielectric capacitors are desired for electronics and electrical power systems because of their fast charge–discharge speed and high‐power density. Nevertheless, dielectric capacitors typically exhibit lower energy densities in comparison to other energy storage systems like batteries or fuel cells. Among dielectrics, antiferroelectrics have shown great promise for high energy density because of their characteristic double hysteresis loops. However, current antiferroelectric capacitors still face challenges of low efficiency and low breakdown strength due to their large hysteresis, which is harmful to energy efficiency and reliability of the system. Herein, by engineering the nanoscale heterogeneity to mitigate hysteresis and controlling orientation to enhance the polarization, the exceptional energy storage performance of antiferroelectric (Pb0.97La0.02)(Zr0.55Sn0.45)O3 epitaxial thin films is demonstrated. Atomic‐resolution transmission electron microscopy and X‐ray reciprocal space mapping confirm the presence of nanoscale structural heterogeneity, characterized by fragmented antipolar nanodomains. These films exhibit remarkable energy densities, reaching up to ≈84.5 J cm−3, coupled with ultrahigh efficiencies of up to ≈98.5% and superior stability, maintaining efficiencies above 92% across a wide field range of ≈5 MV cm−1. Notably, these findings surpass the capabilities of previously reported dielectric materials, opening new avenues for advanced energy storage applications.

Antiferroelectric oxide thin-films: Fundamentals, properties, and applications

“…On the other hand, reducing the difference between E AF and E FA , i.e., reducing electric hysteresis, can decrease the hysteresis area, that is, reduce the energy loss density J loss and increase the energy storage efficiency. Previous studies have demonstrated that introducing nanoscale structural heterogeneity into AFEs generally via chemical doping is an effective approach to lower the energy barrier between the AFE and field-driven FE phases and thus reduce the electric hysteresis [157,[292][293][294]. Increasing saturation polarization or decreasing remnant polarization.…”

“…For instance, Zhang et al [294] demonstrated that the combination of structure heterogeneity and orientation control in relaxor AFE (Pb 0.97 La 0.02 )(Zr 0.55 Sn 0.45 )O 3 thin films can simultaneously achieve high energy storage efficiency (~98.5 %) and energy storage density (~84.45 J/cm 3 ). In that work, introducing La 3+ and Sn 4+ dopants into AFE PbZrO 3 can engineer the structural heterogeneity and disrupt the long-range ordered AFE domains, which can effectively decrease the polarization hysteresis (E AF -E FA ) [294]. By controlling the orientation, the (1 1 1)-oriented films exhibit the largest polarization among (1 1 1)-, (1 1 0)-and (0 0 1)-oriented films and gain the highest energy storage density (~84.45 J/cm 3 ) [294].…”

“…In that work, introducing La 3+ and Sn 4+ dopants into AFE PbZrO 3 can engineer the structural heterogeneity and disrupt the long-range ordered AFE domains, which can effectively decrease the polarization hysteresis (E AF -E FA ) [294]. By controlling the orientation, the (1 1 1)-oriented films exhibit the largest polarization among (1 1 1)-, (1 1 0)-and (0 0 1)-oriented films and gain the highest energy storage density (~84.45 J/cm 3 ) [294].…”