Superior energy storage performance in Bi0.5Na0.5TiO3 based ceramics via synergistic design of multi-size domain construction and multiple phase structures

Abstract

Lead-free dielectric ceramics, as the crucial materials for the development of eco-friendly high pulse power devices, have faced limitations in achieving energy storage performance comparable to lead-based counterparts. A novel strategy was adopted to enhance the energy storage capability of Bi0.5Na0.5TiO3 based ceramics by constructing multiple phase structures and multi-size domain. An ultrahigh energy storage density of 8.0 J·cm−3 and a large efficiency of 88.9 % were achieved. The superior energy storage properties can be attributed to the synergistic effects of multiple phase structures and multi-size domain construction resulted from a significant polarization intensity difference upon Sr(Zr0.2Ti0.8)O3 doping. Even more surprising, the 0.6Bi0.5Na0.5TiO3-0.4Sr(Zr0.2Ti0.8)O3 ceramic exhibited excellent aging resistance, with variation in discharge energy density (Wd) < ±7% over a temperature range from 20 to 150°C, variations in recoverable energy density (Wrec) < ±8.3 %, and efficiency (η) < ±5.6 % over a frequency range from 1 to 50 Hz and across 105 cycles. The finding in this work not only provides an effective candidate for high power pulse capacitors, but also provides ideas for the study of high energy storage performance of BNT and the related lead-free ceramics.