Enhanced energy storage performance of NaNbO3-based ceramics via band and domain engineering

High-performance lead-free energy storage ceramic materials are one of the important materials for environ-mentally friendly electronic devices. Here, lead-free NaNbO3 (NN)-based relaxor ceramics, NaNbO3- xBiMg0.5Hf0.5O3(NN-xBMH, x = 0.05, 0.10, 0.15, and 0.20), were obtained by solid-state reaction method. Our results show that the introduction of BMH greatly improves the relaxor behavior, enhancing domain switching capability. As increasing BMH content, the large band gap leads to improve the breakdown field strength. A high energy storage (Wr = 5.00 J/cm3) and efficiency (eta = 83.1%) were obtained in the NN-0.15BMH ceramic. In addition, the discharge energy density of NN-0.15BMH ceramic can be kept at 3.15 J/cm3 at 300 kV/cm, showing excellent charge and discharge performance. This work confirms that the method of band and domain engineering is a facile strategy for high-performance energy storage ceramics.