Improved energy storage performance and thermal stability in (1−x)(Sr0.7Ba0.255Ca0.045Ti0.9Zr0.1O3)-xBi0.5Na0.5TiO3 ceramics with multiple synergistic design

Abstract Developing dielectric capacitors with high power-density, fast charge-discharge rates and excellent temperature stability has become a key component of advanced pulsed power electronic systems. Here, lead-free (1− x )(Sr 0.7 Ba 0.255 Ca 0.045 Ti 0.9 Zr 0.1 O 3 )- x Bi 0.5 Na 0.5 TiO 3 ceramics were designed and prepared to improve the energy storage performance via multiple synergistic strategy. On the one hand, the disordered distribution of multiple ions at perovskite A and B sites increases the molar configurational entropy and thus enhances the degree of phase transition relaxation and the breakdown electric field. On the other hand, the coexistence of rhombohedral ( R ), tetragonal ( T ) and cubic ( C ) phases can not only provide more polarization rotation pathways but also hinder the grain and domain growth. In addition, the introduction of Bi 3+ ions with 6 s lone-pair electrons can increase the polarization. As a result, high recoverable energy storage ( W rec ) of 4.29 J cm −3 and efficiency ( η ) of 90.1% were realized in the ceramic with x = 0.4 at a moderate electric field of 404 kV cm −1 . Moreover, the ceramic exhibited superior temperature stability across a broad temperature range up to 140 °C and outstanding fatigue resistance up to 10 6 cycles.