Nanoscale structural heterogeneity enhanced temperature-stable energy storage in Bi0.5Na0.5TiO3-based relaxor ceramics via domain and defect dipoles engineering

Ceramic-based dielectric capacitors are showing great potential in advanced high-power applications. However, simultaneous achievement of high energy density (W-rec) and temperature stability is still a main bottleneck. Herein, an extraordinary nanoscale structural heterogeneity is developed to promote temperature-stable energy storage in Er/Mn co-doped Bi0.5Na0.5TiO3 based ceramics via domain and defect dipoles engineering. The composition-driven domain reconstruction by Er/Mn co-doping can induce internal random fields with rapid response to the electric field, and thus enhance Delta P and eta. Meanwhile, the donor-accpetor Er/Mn doping could manipulate defect dipoles coupling to resist the applied field evolution to elevate BDS and eta. Besides, the improved relaxor feature and core-shell structure give rise to the enhanced temperature stability. Ceramics with 2 mol % Er2O3 demonstrate high W-rec similar to 2.79 J/cm(3), large efficiency similar to 89.4% and outstanding dielectric stability within 70-500 degrees C. The proposed nanostructural heterogeneity was verified as a promising pathway to manufact temperature-stable energy storage ceramics.