Ultrahigh energy storage density in (Bi0.5Na0.5)0.65Sr0.35TiO3-based lead-free relaxor ceramics with excellent temperature stability

Developing environmentally friendly lead-free dielectric ceramics with ultrahigh energy storage performance is fundamental to next-generation high-power capacitors but challenging as well. Herein, a record-breaking ultrahigh energy efficiency η of 97.8%...

Superior energy storage performance in (Bi0.5Na0.5)TiO3-based lead-free relaxor ferroelectrics for dielectric capacitor application via multiscale optimization design

Dielectric capacitors have attracted growing attention because of their important applications in advanced high power and/or pulsed power electronic devices. Nevertheless, the synergistic enhancement of recoverable energy storage density (Wrec > 10 J/cm3) and efficiency (η > 80%) is still a great challenge for lead-free dielectric bulk ceramics. Herein, by introducing complex perovskite compound (Bi0.9Na0.1)(Fe0.8Ti0.2)O3 with a smaller tolerance factor into an NaNbO3 matrix (NN-BNFT), we have achieved and explored stable relaxor antiferroelectric ceramics with enhanced relaxor behavior. Of particular importance is the composition of 0.88NN-0.12BNFT, which exhibits a large electric breakdown strength Eb of 87.3 kV/mm, an ultrahigh Wrec of 12.7 J/cm3, and a high efficiency η of 82.5%, as well as excellent thermal reliability and an ultrafast discharge speed, resulting from the dense microstructure, the moderate dielectric constant, the reduced grain size, the dielectric loss, and the sample thickness. The outstanding energy storage properties of NN-BNFT display great promise in advanced dielectric capacitors for energy storage applications.

Ultrahigh Energy Storage Density and High Efficiency in Lead-Free (Bi0.9Na0.1)(Fe0.8Ti0.2)O3-Modified NaNbO3 Ceramics via Stabilizing the Antiferroelectric Phase and Enhancing Relaxor Behavior.

Sodium niobate (NaNbO3, NN)-based lead-free antiferroelectric (AFE) ceramics are currently the focus of most attention on account of their outstanding energy storage density. Nevertheless, the high loss energy density (Wloss) by unique field-induced AFE-ferroelectric (FE) phase transition in pure NN ceramic and low breakdown electric field (Eb) largely restrict their practical application. Here, a combined optimization strategy was aimed at ameliorating energy storage characteristics of NN-based ceramics. First, the introduction of BiFeO3-SrTiO3 binary solid solution in pure NN ceramics destroys the long-range polar ordering and reduce the tolerance factor (t), thus reducing the polarization hysteresis, stabilizing the AFE phase and enhancing the energy storage efficiency. Then, the two-step sintering method was used to improve the compactness of ceramics and reduce the grain size. Finally, the VPP method was used to reduce the porosity, and thin the ceramic disk to a thickness of ∼100 μm. The high compactness and small thickness could effectively enhance the maximum breakdown electric field of ceramics. Ultimately, the optimum energy storage characteristics were obtained by the improvement of a combined optimization strategy, namely, an exceptional recoverable energy storage density (Wrec = 5.29 J/cm3) and efficiency (η = 82.1%) at a very high breakdown electric field (Eb = 380 kV/cm). This combined optimization strategy establishes a universal approach to ameliorate the energy storage characteristics of NN-based AFE ceramics for energy storage.

A Combined Optimization Strategy for Improvement of Comprehensive Energy Storage Performance in Sodium Niobate-Based Antiferroelectric Ceramics.

Enhanced antiferroelectric-like relaxor ferroelectric characteristic boosting energy storage performance of (Bi0.5Na0.5)TiO3-based ceramics via defect engineering

Ming Huang

Papers

Ultrahigh energy storage density in lead-free relaxor antiferroelectric ceramics via domain engineering