Effects of BaxSr1−xTiO3 ceramics additives on structure and energy storage properties of Ba0.4Sr0.6TiO3–BaO–B2O3–Al2O3–SiO2 glass-ceramic

• The maximum energy storage density of the BST composites increases to 3.1 J/cm3.
• The dielectric constant can be increased from 56 to 611 as the BST ceramic added.
• The microstructure is modified by adding an appropriate content of BST ceramics.
• The BDS of the samples synthesized by ceramic and glass-ceramic can be improved.
• The relationship between breakdown strength and dielectric constant is studied.

A series of Ba0.4Sr0.6TiO3–BaO–B2O3–Al2O3–SiO2 (BST40-BBAS) glass-ceramics with different content of BaxSr1−xTiO3 (x = 0.4, 0.7 and 0.9) additives were synthesized by solid state sintering process. The relationships between phase structure, microstructure and dielectric properties were investigated. The XRD results illustrated that all the peaks of BST phases shifted to lower angle with the increasing of BaxSr1−xTiO3 additives. Moreover, the shift tendency of peaks became more obvious as the x increased. The microstructure results exhibited that an appropriate composition of BaxSr1−xTiO3 additives could cut off the contact among the BST glass powders, which effectively restrained the abnormal growth of the BST glass-ceramics. As the BaxSr1−xTiO3 additives increased, the dielectric constant of the glass-ceramics increased from 56 to 611 and the Curie temperatures of the BST glass-ceramic specimens moved to high temperature. The breakdown strength (BDS) reduced from 853 kV/cm to 405 kV/cm with the increase of BST ceramics concentration. In order to obtain a maximum energy density, the relationship between dielectric breakdown strength and dielectric constant was studied. The glass-ceramic composites synthesized by BST40-BBAS glass-ceramic and BaxSr1−xTiO3 ceramics could effectively improve the energy storage density. A maximum of the calculated energy density reached up to 3.1 J/cm3, which was improved by 1.8 times as compared with that of the pure BST40-BBAS glass-ceramic (1.74 J/cm3).