Mn-Doped NaNbO3/Na0.5Bi0.5TiO3 Lead-Free Ferroelectric Ceramics with Enhanced Energy Storage Performance

NaNbO3-based ferroelectric composites are regarded as a highly promising typical energy storage material. In this work, 0.02xMnO2−(1−x)NaNbO3−xBi0.5Na0.5TiO3 composites were prepared by the solid-state sintering method and their microstructure, energy storage performance, and temperature stability were analyzed. As observed by the SEM images, the addition of Bi0.5Na0.5TiO3 to NaNbO3 in appropriate amounts can effectively suppress grain growth, which is beneficial for improving the breakdown field strength. When x = 0.3, an optimal value of 210 kV/cm is achieved. Meanwhile, as 2θ = 33.2°, the most intense XRD peak can be observed, indicating excellent solid solubility between the phase components. Consequently, 0.006MnO2–0.7NaNbO3–0.3Bi0.5Na0.5TiO3 composites demonstrated an impressive discharging storage density of 2.464 J/cm3 and a considerable energy storage efficiency of 85.8%. In addition, within the temperature range of 30–80 °C, the fluctuation in energy storage density remains below 10%. All the above performances indicate that this type of material exhibits excellent practicality in the field of pulse power supply.