Enhanced recoverable energy storage density and efficiency in (1 − x)Ba0.85Ca0.15Zr0.1Ti0.9O3-xSrTiO3-MnO2 lead-free ceramics

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2022-03, Vol.10 (10), p.3876-3885
• Main Authors: Yang, Wenjin, Huang, Fengzhen, LiHuai Shu, Yang, YuLong, Gong, Baolian, Lu, Xiaomei, Zhu, Jinsong
• Format: Article
• Language: English
• Subjects: Barium titanates; Capacitors; Ceramics; Dielectric breakdown; Dielectric strength; Discharge; Electronic devices; Energy storage; Ferroelectric materials; Ferroelectricity; Flux density; Lead free; Manganese dioxide; Polarization; Sintering aids; Solid solutions
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d2tc00056c

Lead-free dielectric capacitors have attracted much attention in pulsed power systems due to their rapid charge/discharge rate. However, their recoverable energy storage density (Wrec) and efficiency (η) still need further improvement to meet the requirements for their application in energy storage devices. In this article, SrTiO3 (ST) and MnO2 were introduced to Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) to obtain a (1 − x)BCZT-xST solid solution, where morphotropic phase boundary ferroelectric BCZT possesses high polarization, paraelectric ST has a high dielectric breakdown strength (Eb), and the 0.3 mol% MnO2 contributes to the dense and fine-grained microstructure as a sintering aid. A high Eb of 436 kV cm−1, large ferroelectric polarization of 33.0 μC cm−2, and small remnant polarization of 2.1 μC cm−2 were obtained in the 0.3BCZT-0.7ST ceramic. As a result, a large Wrec of 5.36 J cm−3 and a high η of 82.2% were simultaneously achieved. Moreover, the 0.3BCZT-0.7ST ceramic exhibits a large DC discharge energy density of 5.63 J cm−3 and an ultrafast discharge time (t0.9) of 46 ns, and therefore an extremely high power density (PD) of 367.8 MW cm−3 and a large current density (CD) of 1337.6 A cm−2, two essential parameters for practical application in high-power devices. These results highlight the potential applications of the 0.3BCZT-0.7ST ceramic in pulsed power capacitors with high energy storage density and provide a comprehensive guideline for the control of BaTiO3-based dielectric capacitors.