BNT-ST-based ceramics have been widely studied due to their excellent energy storage performance, such as large spontaneous polarization, high energy efficiency, and good relaxation performance. However, the breakdown strength of BNT-ST based ceramics is relatively low, which seriously restricts the improvement of their energy density. In order to enhance the breakdown strength of BNT-ST-based ceramics, a two-stage sintering combined with chemical coating SiO₂ stepwise optimization strategy is introduced. Two stage sintering can effectively suppress grain boundary migration and provide sufficient energy for grain boundary diffusion, achieving ceramic densification while suppressing grain growth. The combination of two-stage sintering and chemical coating of SiO₂ not only effectively inhibits grain growth, but also forms a layer of SiO₂ with high breakdown potential barriers at the ceramic grain boundaries, significantly enhancing the breakdown strength and energy density of BNT-ST-based ceramics. The relevant research findings were published in the Journal of the European Ceramic Society (JCR Q1) titled "Enhancing energy storage density of BNT-ST-based ceramics by a stepwise optimization strategy on the breakdown strength".

Fig. 1. Strategy diagram for achieving excellent energy storage properties via a stepwise optimization strategy combining two-step sintering and chemical coating

Fig. 2. (a) and (b) HR-TEM images of BNT-ST @ Si-TSS powder; (c) TEM images of BNT-ST @ Si-TSS ceramic; (d) EDS line profiles of Si, Bi, Sr and Ti along line AB in (c).

Fig. 3. (a) Unipolar P-E loops of all ceramic samples at room temperature and 10 Hz under 100 kV/cm; (b) unipolar P-E loops of all ceramic samples at different electric fields with room temperature and 10 Hz; (c) maximum W_dis and E_b of all ceramic samples at different electric fields with room temperature and 10 Hz measured up to E_b; (d) W_dis and E_b values relative to different samples.

Fig. 4. (a) Unipolar P-E loops of BNT-ST @ Si-TSS ceramic measured at 120 kV/cm after various cycles. (b) W_dis and η values versus cycles. (c) Unipolar P-E loops of BNT-ST @ Si -TSS ceramic measured at 120 kV/cm over the temperature range from 30 to 140 ℃. (d) W_dis and η values versus temperature.

Authors: Xinheng Li¹，Chaoqiong Zhu^1,*，Shiheng Li，Aoyu Li，Lanqing Liang，Ziming Cai^*，Peizhong Feng

Link: https://www.sciencedirect.com/science/article/pii/S0955221924003297

DOI: 10.1016/j.jeurceramsoc.2024.04.023