Enhanced dielectric and energy-storage performance of nanocomposites using interface-modified anti-ferroelectric fillers

Polymer-based 0–3 composites filled with ferroelectric ceramic particles have exhibited prominent dielectric responses and energy-storage performance, and are expected to be promising materials for high-performance, energy-storage capacitors in advanced electric systems. Unfortunately, low discharging efficiency hampers their practical application due to the high remnant polarization and interface related dielectric loss. In the present work, an anti-ferroelectric ceramic (Pb_0.97La_0.02)[Zr_0.63(Sn_0.3Ti_0.07)O₃] (PLZST) was prepared as the filler due to their intrinsic ultra-low dielectric loss and remnant polarization. Meanwhile, 3-aminopropyltriethoxysilane (KH550) was used to modify the surface of PLZST to enhance the interfacial compatibility between the PLZST filler and the polymer matrix. Enhanced dielectric permittivity, lowered loss, increased breakdown strength, and energy density were obtained at a relatively low loading content of the modified fillers (m-PLZST). Specifically, a considerably high energy density of 12.8 J/cm³ was achieved in a thin film with 8.0 wt% m-PLZST fillers. In comparing the properties of the composites filled with surface modified PLZST (m-PLZST) and pristine PLZST, the significant performance enhancement is well addressed with the accompanying reduction in loss, lowered remnant polarization, and depressed interfacial polarization. This result correlates to the anti-ferroelectric characteristics of the filler and enhanced compatibility from the surface modification.