Enhanced thermal and frequency stability and decent fatigue endurance in lead-free NaNbO3-based ceramics with high energy storage density and efficiency

作者：Chen, Hongyun; Shi, Junpeng; Dong, Xiaoyan; Pang, Feihong; Zhang, Hailin; Chen, Xiuli^*; Zhou, Huanfu^*

来源：Journal of Materiomics, 2022, 8(2): 489-497.

DOI：10.1016/j.jmat.2021.06.0

• Breakdown electric field
• Excellent dielectric stability
• Charge-discharge performance
• Potential value

Lead-free ceramic capacitors have the application prospect in the dielectric pulse power system due to the advantages of large dielectric constant, lower dielectric loss and good temperature stability. Nevertheless, most reported dielectric ceramics have limitation of realizing large energy storage density (W-rec) and high energy storage efficiency (eta) simultaneously due to the low breakdown electric field (E-b), low maximum polarization and large remanent polarization (P-r). These issues above can be settled by raising the bulk resistivity of dielectric ceramics and optimizing domain structure. Therefore, we designed a new system by doping (Bi0.5Na0.5)(0.7)Sr0.3TiO3 into 0.9NaNbO(3)-0.1Bi(Ni0.5Zr0.5)O-3 ceramics, which simultaneously obtained a higher bulk resistivity by decreasing the grain size and achieved a smaller Pr by optimizing domain structure, thus the better E-b of 530 kV/cm and W-rec of 6.43 J/cm(3) were achieved, eta was improved from 34% to 82%. Besides, the 0.4BNST ceramics show excellent temperature, frequency and fatigue stability under the conditions of 20-180 degrees C, 1-100 Hz and 10(4) cycles, respectively. Meanwhile, superior power density (P-D = 107 MW/cm(3)), large current density (C-D = 1070 A/cm(2)) and discharge speed (1.025 mu s) were achieved in 0.4BNST ceramic. Finally, the charge-discharge performance displayed good temperature stability in the temperature range of 30 degrees C-180 degrees C. The above results indicated that the ceramics have potential practical value in the field of energy storage capacitor.

• 单位
  桂林理工大学