Realizing high energy density and superior charge-discharge characteristics in NN-10BT-based ceramics

The low recoverable energy storage density (Wrec) of bulk ceramics has long limited their miniaturization and lightweight development. Here, we designed the (1-x)(0.90NaNbO3-0.10BaTiO3)-xNa0.2Bi0.4La0.2TiO3 (NN-10BT-xNBLT) ceramics. With the introduction of NBLT, the dielectric breakdown strength (BDS) of NN-10BT-based ceramics increased from 174.8 kV/cm to 289.1 kV/cm. A promising finding is that the NN-10BT-15NBLT ceramic has an ultrahigh energy storage density W of 3.42 J/cm3 and a large energy storage effi-ciency eta of 78.9%, as well as excellent frequency and thermal stability. The NN-10BT-15NBLT ceramic, on the other hand, has an outstanding current density CD of 1021.21 A/cm2 together with a high power density PD of 102.12 MW/cm3 at 200 kV/cm. Most importantly, the variation of charge-discharge properties (CD and PD) is only-7.8% after 104 cycles, suggesting that the capacitor has potential practical application significance.