Bi0.2Sr0.7TiO3–doped Bi0.5Na0.5TiO3–based lead-free ceramics with good energy storage properties

Dielectric capacitors have received much attention and are used in pulsed power supplies, electronic circuits etc. due to their fast charge/discharge rate and high-power density. However, the large-scale application of dielectric capacitors is limited by the energy storage density. Bi0.5Na0.5TiO3 (BNT)-based ceramic capacitors are suitable materials for the preparation of dielectric capacitors due to their large spontaneous polarization. Therefore, the use of chemical modification to improve the energy storage density of BNT-based ceramics is a current research hotspot. In this work, the (0.9-x)Bi0.5Na0.5TiO3-0.1Ba0.7Ca0.3TiO3-xBi0.2Sr0.7TiO3 ceramics (BNT-BCT-xBST) were prepared. BST was used to modulate the relaxor characteristics of BNT-BCT. When the content of BST is 6%, the ceramic has a recoverable energy storage density of 2.73 J/cm3 and an energy storage efficiency of 85% at 280 kV/cm and a power density of 33.3 MW/cm3 at 150 kV/cm. This work proves that BNT-BCT-0.06BST is a good candidate for dielectric capacitor.