Dielectric temperature stability and energy storage performance of BST-based lead-free ceramics for X8R capacitors

(1-x)Ba0.8Sr0.2TiO3-xBi(Mg0.5Zr0.5)O-3 [(1-x)BST-xBMZ] relaxor ferroelectric ceramics were prepared by solid-phase reaction. In this work, the phase structure, surface morphology, element content analysis, dielectric property, and energy storage performance of the ceramic were studied. 0.84BST-0.16BMZ and 0.80BST-0.20BMZ have good dielectric temperature stability and low dielectric loss (0-200 degrees C, tan delta<0.01), meeting the X8R capacitor standard (- 55-150 degrees C, Delta C/C-25 degrees C <= +/- 15%). In addition, 0.84BST-0.16BMZ also has high recoverable energy storage density (W-rec) of 2.31 J/cm(3) and energy storage efficiency of 83% (eta) at 320 kV/cm, compared to pure Ba0.8Sr0.2TiO3 ceramic, the maximum breakdown strength (BDS) of 0.84BST-0.16BMZ increased from 78 to 320 kV/cm, which is four times that of pure Ba0.8Sr0.2TiO3 ceramic, and after 10(7) cycles at room temperature, the recoverable energy storage density has almost no change, showing excellent fatigue resistance. The study provides a viable approach for the development of new lead-free energy storage ceramic capacitor and Class II-type ceramic capacitor.