NaNbO₃-based antiferroelectric multilayer ceramic capacitors for energy storage applications

Antiferroelectric materials feature electric-field-induced phase transitions followed by a large polarization change characterized by double polarization hysteresis loops. Therefore, antiferroelectrics are engaging for high-energy density and high-power density applications, especially in the form of multilayer ceramic capacitors (MLCCs). However, the development of lead-free antiferroelectrics with stable double hysteresis loops is still challenging, especially for compositions based on NaNbO₃. To this end, we have prepared MLCCs with the newly developed antiferroelectric composition 0.90NaNbO₃-0.06SrSnO₃-0.04(Na_0.5Bi_0.5)TiO₃. The double hysteresis loops were determined at 24 kV/mm in the temperature range of 25–150 °C, with resulting recoverable energy storage ranging from 1.16 to 1.42 J/cm³, respectively. Moreover, the energy efficiency is rather constant at 0.4 in the same temperature range. Finally, the MLCCs exhibit resistance to electric field cycling and could withstand up to 1000 cycles. These results verify that NaNbO₃-based antiferroelectrics in the form of MLCCs are promising for use in applications.