Achieving Superior Energy Storage Performance in PLZST Ceramics via Relaxor Ferroelectric Composite Strategy

Dielectric capacitors featuring high energy density and excellent temperature stability are vital to the miniaturization and reliability of high-power electronic systems. Antiferroelectrics (AFEs) exhibit high polarization through field-induced phase transition. However, their antiferroelectric-ferroelectric phase transition electric field (E_AFE-FE) usually exceeds the dielectric breakdown strength, severely restricting their practical energy storage capability. To address this issue, we propose an antiferroelectric/relaxor ferroelectric composite strategy that effectively reduces the E_AFE-FE by tuning the phase transition energy barrier, thereby facilitating field-induced polarization switching. The Pb_0.94La_0.04(Zr_0.84Sn_0.15Ti_0.01)O₃/2 wt % 0.8Ba(Zr_0.1Ti_0.9)O₃-0.2 Bi(Zn_2/3Ta_1/3)O₃ (PLZST/2BZT) composite ceramics exhibit a high recoverable energy storage density (W_rec) of 9.3 J cm^-3 and an energy storage efficiency (η) of 85% when subjected to a breakdown electric field of 325 kV cm^-1. This remarkable performance is owing to the reduced phase transition energy barrier and the enhanced interfacial polarization, which collectively strengthen polarization response. Notably, the PLZST/2BZT ceramics also exhibit exceptional temperature stability, maintaining W_rec above 6.5 J cm^-3 and η invariably surpassing 81% over a broad temperature range of -20 to 140 °C under a 320 kV cm^-1 electric field. These results highlight the effectiveness of the AFE/relaxor ferroelectric composite strategy for achieving high-performance dielectric ceramics, providing valuable insights into the design of high-performance capacitors for advanced dielectric materials and high-power electronic devices.