Ultrahigh energy storage density and superior discharge power density in a novel antiferroelectric lead hafnate

Abstract

Dielectric capacitors have been widely applied to pulse charge-discharge systems with medium energy density and high power density. In this work, (Pb1-3x/2Lax)Hf0.96Ti0·04O3 (PLHT) antiferroelectric (AFE) ceramics were synthesized by a solid-state solution. The field-induced AFE to ferroelectric transitions with double polarization-electric field hysteresis loops were observed for all studied components. The energy storage efficiency of PLHT ceramics was significantly improved by doping La3+. The sample of x = 0.05 (PLHT-0.05) exhibits excellent energy storage properties with a record-high recoverable energy storage density of 11.2 J/cm3, and a high energy efficiency of 88.9% achieved at an electric field of 360 kV/cm. The ceramic exhibits superior frequency and thermal stability against external environmental change. Besides, a record high discharge energy density (8.51 J/cm3) with an ultrafast discharge rate (t0.9<211 ns) was obtained under 360 kV/cm at room temperature in PLHT-0.05 ceramic. Underdamped discharge test shows the sample achieves an ultrahigh current density of 2098 A/cm2 and a giant power density of 378 MW/cm3, suggesting a significant advantage compared with the previously reported ceramic systems. The significant improvement implies the PLHT AFE ceramics can provide a realistic solution for high-power energy storage capacitors.