Decreasing polar-structure size: Achieving superior energy storage properties and temperature stability in Na0.5Bi0.5TiO3-based ceramics for low electric field and high-temperature applications

It is a grand challenge to achieve high energy density (W) and efficiency (eta) simultaneously under a low electric field (LE) to obtain new high energy storage capacitors. Similar to anti-ferroelectrics, the (1-x)NBT-xBaMg(1/3)Nb(2/3)O(3) relaxor material exhibits a non-linear dependence on electric field, which is caused by a reversible field-induced phase transition. This leads to high W (2.37 J/cm(3)) and. (81.5 %) under a LE of 155 kV/cm, which makes it superior to other bulk ceramics. Combining large polarizability of Ba2+ in A-site and local structural heterogeneity on the B-site by Mg1/3Nb2/34+, enhanced relaxor behavior and decreased polar-structure size were induced in (1-x)NBT-xBaMg(1/3)Nb(2/3)O(3) ceramics. The permittivity, nevertheless, stays high at similar to 2273 +/- 15 %. Furthermore, the electrical properties become stable in a wide temperature range from 44 396. C for the sample with x=0.15. In addition, high current density/C-D (450 A/cm(2)), power density/P-D (23 MW/cm(3)) and discharge density/W-D (0.57 J/cm(3)) were realized tested with pulse discharge testing. Our work will provide a development guidance for dielectric energy storage ceramics at low field and high fields with excellent temperature stability.