Effective strategy to optimize energy storage properties in lead-free (Ba_0.3Sr_0.7)TiO₃ ceramics by the suppression of leakage current

Ceramic capacitors require promising energy storage properties to meet the demands of electronic industry which can be tailored by ferroelectric polarization and electrical breakdown strength. Electrical breakdown exhibits close relation to leakage current in advanced dielectric materials when stimulated by high levels of electric field. The suppression of leakage can be an effective strategy to elevate dielectric breakdown. In this work, Zr ions were employed to replace Ti ions in Ba_0.3Sr_0.7TiO₃ ceramics to achieve the improvement of dielectric breakdown and then increase energy storage ability. Zr doping can obviously reduce the leakage current more than an order of magnitude by blocking the path between two adjacent Ti ions and increasing the distance of electron hopping. A promising energy storage density can be obtained with good fatigue endurance upto cycles of 10⁵. This indicates that the strategy of suppressing leakage by trace amount of Zr doping is an effective approach to tailor energy storage behavior of dielectric ceramics.