Enhanced energy storage properties with excellent stability in BST-BLZS relaxor ceramics

Abstract

Ba0.4Sr0.6TiO3 is regarded as one of promising material for energy-storage capacitors. However, its dielectric breakdown strength is relatively low (∼ 15 kV/mm) and remnant polarization (Pr) is large. These deficiencies lead to inadequate recoverable energy storage density (Wrec) and efficiency (η). Herein, novel (1-x)Ba0.4Sr0.6TiO3-xBi0.5La0.5(Zn0.5Sn0.5)O3 (BST-xBLZS, 0.08 ≤ x ≤ 0.14) ceramics were prepared to introduce relaxation and obtain smaller average grain size compared with pure BST. This strategy effectively inhibits the production of oxygen vacancies and titanium ions from changing valence, thereby increasing resistivity and reducing grain size, which result in the enhanced BDS. Meanwhile, enhanced relaxation results in near-zero Pr and η is highly improved. When x = 0.12, BDS was significantly enhanced to 48 kV/mm and high Wrec (2.76 J/cm3) with preferable η of 92% was achieved simultaneously. Excellent temperature and frequency stability of energy storage performance were obtained either. Moreover, the 0.88BST-0.12BLZS ceramic also possesses large power density (PD = 48.4 MW/cm3) with good temperature and fatigue stability. Meanwhile the fast discharge rate (t0.9 around 200 ns) was obtained. These properties show that 0.88BST-0.12BLZS relaxor ceramic exhibits great prospects for practical pulse power applications.