Enhancement of dielectric properties and energy storage performance in 3Y-TZP ceramics with BaTiO3 additives

With the fast charge-discharge speed and ultrahigh power density, electrostatic energy storage materials offer great potential in the applications for pulsed power systems. As a very important member of structural ceramics, 3Y-TZP (3 mol% Y₂O₃ doped tetragonal zirconia polycrystals) has shown extraordinary mechanical properties. However, the research on their energy storage performance is still lacking. Herein, a ferroelectric phase, BaTiO₃ (BT), was introduced and demonstrated to improve the dielectric properties and energy storage performance of 3Y-TZP ceramic matrix via the conventional solid-state reaction method. With increasing the BT content from 0 to 15 mol%, the permittivity of the composite ceramics could be effectively increased from 40.2 to 64.1 measured at 1 kHz. Simultaneously, the dielectric loss could be effectively decreased by depressing the response of charged defects, which was further interpreted by the thermally stimulated depolarization current technique. Meanwhile, the breakdown strength showed a typical increase-then-decrease trend with increasing BT content, and reached their maximum values when doped with 7 mol% BT. Together with the enhancement of dielectric properties, the 7 mol% BT-doped 3Y-TZP ceramics exhibited a maximum energy storage density of 0.42 J/cm³, which was approximately 150% larger than that of the pure 3Y-TZP ceramics.