Achieving excellent energy storage performance of K1/2Bi1/2TiO3-based ceramics via multi-phase boundary and bandgap engineering

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 473; p. 145314
• Main Authors: Zhang, Manlin, Zhu, Mankang, Chang, Ziliang, Li, Yexin, Zheng, Mupeng, Hou, Yudong, Zhou, Qiyuan, Chao, Xiaolian, Yang, Zupei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2023
• Subjects: Band gap; Dielectric breakdown strength; Dielectric energy storage; K1/2Bi1/2TiO3; Leakage current; Phase boundary; K1/2Bi1/2TiO3; Dielectric breakdown strength; Leakage current; Band gap; Dielectric energy storage; Phase boundary
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2023.145314

•0.9 K1/2Bi1/2TiO3-0.1Na1/2Bi1/2ZrO3 behaves a relaxor with multiphase coexistence.•SH addition improves the breakdown strength via bandgap and grain boundary modulation.•Sample SH6 realizes ultrahigh ΔP of 47.8 µC/cm2 and Wr of 5.33 J/cm3 under 290 kV/cm. As a latent candidate for energy storage material, K1/2Bi1/2TiO3 (KBT) attracts the interest of researchers due to its high saturation polarization and inherited relaxor feature. But the low dielectric breakdown strength Eb of KBT-based ceramics limits the potential for the dielectric energy storage application. Efficient improving on the Eb while keeping the field-induced polarization difference ΔP at high level is of significance for designing KBT-based dielectric energy storage ceramics. In this work, by constructing a ferroelectric -relaxor phase boundary in KBT- Na1/2Bi1/2ZrO3 (NBZ) and introducing the recipient ferroelectric SrHfO3 (SH) with wide bandgap, the synergistic improvement on the Eb and ΔP were realized. Our experimental results reveal that, 0.9KBT-0.1NBZ behaves as a strong ferroelectric relaxor, and SH addition into 0.9KBT-0.1NBZ increases the band gap and suppresses the leakage current, thus enhances the dielectric breakdown strength Eb significantly. At SH addition of 6.0 mol.%, excellent polarization behavior and energy storage performance were achieved: a super-large ΔP of 47.8 µC/cm2, an ultrahigh recoverable energy density Wr of 5.33 J/cm3, and a high efficiency above 75%. Our work proposes a novel design route to construct KBT-based ceramics as a candidate for energy storage capacitors.