Energy-storage capacitors based on relaxation ferroelectric ceramics have attracted a lot of interest in pulse power devices. How to improve the energy density by designing the structure of ceramics through simple approaches is still a challenge. Herein, enhanced energy-storage performances are achieved in relaxation ferroelectric 0.9 (0.94Na0.5Bi0.5TiO3-0.06BaTiO3)-0.1NaNbO3 (NBT-BT-NN) ceramics by tuning sintering temperature. The original observation based on Kelvin probe force microscopy (KPFM) presented that the sintering temperature has a key effect on the electrical homogeneousness of the ceramics. It is found that a high electrical homogeneousness can induce quick and active domain switching due to the weakening of the constraint from built-in fields, resulting in a big polarization difference. This work provides a feasible strategy to design high-performance energy-storage ceramic capacitors.
Keywords: Na0.5Bi0.5TiO3; dielectric ceramics; energy-storage properties; sintering temperature.