Reducing applied field in NBT-based high energy-storage ceramics via B-site entropy regulation

Recently, ceramics have raised much interest for high-power and high-energy capacitors applications. The W-rec (recoverable energy density) generally increases with applied E (electric field). Thus, the high-field properties must be excellent. Due to enhanced degradation, lower fields would be, nevertheless, preferable. We proposed a novel strategy to improve simultaneously the tolerance factor and configurational entropy based on the composition of (1-x)NBT-xBMZNT. This leads to a high Wrec (1.21 J/cm(3)) and a high efficiency. (86%) under a low E of 100 kV/cm, which is superior to other ceramic components. The discharge test furthermore illustrates a high discharge Wd (>0.8 J/cm(3)) over the temperature range from 20 to 160 degrees C caused by the high permittivity similar to 2700 +/- 15% from 50 degrees C to 370 degrees C. XRD and Raman results present that BMZNT can fully diffuse into the NBT lattice when x < 0.18. Furthermore, BMZNT addition also increases the lattice symmetry and volume. Modulus M. and Piezo-Force-Microscopy (PFM) results demonstrate that sheetlike domains gradually become fragmented to PNRs (polar nanoregions), leading to their rapid response to the applied E. Our work will provide a entropy regulation strategy to reduce the applied field without compromising the energy-storage performance.