Sodium Bismuth Titanate-Based Perovskite Ceramics With High Energy Storage Efficiency and Discharge Performance

Designing dielectric materials with the tremendous energy storage density is fundamentally important for developing pulse power capacitors. An effective approach was proposed to favorably modify the dielectric energy storage properties ( E S P ) of Bi 0.5 Na 0.5 TiO 3 ceramics using CaTiO 3 incorporation. The dielectric breakdown strength was effectively enhanced, and simultaneously the relaxor behavior was optimized to lower the remnant polarization, which is resulted from the decreased grains size with the introduction of Ca 2+ ion. Remarkably, at a CaTiO 3 doping level of 0.2, a 0.8Bi 0.5 Na 0.5 TiO 3 -0.2CaTiO 3 (0.8BNT-0.2CT) ceramic obtained both high energy storage density ( W total ) of ∼1.38 J/cm 3 together with excellent efficiency ( η ) of ∼91.3%. Furthermore, an ultrafast discharge response speed ( t 0.9 ) ∼ 94 ns was achieved in 0.8BNT-0.2CT ceramic, as well as tremendous current density ( C D ∼1520 A/cm 2 ) and power density ( P D ∼115 MW/cm 3 ). This study not only revealed the superior ESP mechanism as regards Bi 0.5 Na 0.5 TiO 3 based ceramics but also provided candidate materials in pulse power capacitor devices. • The grain size of BNT becomes uniformly and decreases obviously upon CT doping. • The 0.8BNT-0.2CT ceramics showed a high ferroelectric stability at 10–500 Hz and 10 4 c. • The 0.8BNT-0.2CT exhibited an excellent W rec of 1.26 J/cm 3 and ƞ of 91.3% at 150 kV/cm. • The 0.8BNT-0.2CT ceramics showed a high P D of 116 MW/cm 3 and fast t 0.9 of 94 ns.