Optimized energy storage properties of BaTiO_3-based ceramics with enhanced grain boundary effect

摘要

Energy storage dielectric ceramics play a more and more important role in power or electronics systems as a pulse power material, and the development of new technologies has put forward higher requirements for energy storage properties. Here, the sol-gel method was used to synthetize the 0.9BaTiO_3-0.1Bi(Mg_(1/2)Zr_(1/2))O_3 (0.9BT-0.1BMZ) precursor powder and 0.9BT-0.1BMZ ceramics with pseudocubic phase was obtained. The 0.9BT-0.1BMZ dielectric ceramics possessed a strong relaxation behavior with 1.64 relaxation degree (g) and 0.15 eV relaxation activation energy (E_a) fitted by modified Curie-Weiss law and Vogel-Fulcher formulas, respectively. The most important was that by controlling the grain size to be reduced, the discharge energy storage density had been improved to 2.0 J/cm~3 with high breakdown strength (325 kV/cm). In addition, the comprehensive analysis of electric field distributions, breakdown paths, and impedance spectra was illustrated the enhanced grain boundary effect can improve the energy storage performance obviously.