A new family of sodium niobate-based dielectrics for electrical energy storage applications

Although tremendous achievements have been made in enhancing recoverable energy storage density (W _rec ) of lead-free dielectric ceramics for electrical energy storage applications in recent years, these ceramics with high W _rec still have two disadvantages: complex chemical composition and difficult preparation process. In this work, we selected NaNbO ₃ (NN)-based ceramics as base materials and used Bi ₂ O ₃ as a sintering aid to reduce porosity and enhance dielectric breakdown strengths. Encouragingly, high W _rec , simple chemical composition and facile preparation process were simultaneously realized in 0.77NaNbO ₃ -0.23BaTiO ₃ (0.77NN-0.23BT) ceramics. A large W _rec of 1.5 J cm ⁻³ at 175 kV cm ⁻¹ and excellent thermal stability (variation of W _rec < 15% over the temperature range of 20˜140 °C) were simultaneously achieved in 0.77NN-0.23BT ceramics. More importantly, this work could bring out the development of a series of NN-based ceramics for electrical energy storage in the future such as NN-ABO ₃ (A = Ca and Sr; B = Ti and Zr).