Modification of sodium niobate energy storage ceramics via doping with a high-entropy phase

Abstract

With the miniaturization and lightweight development of electronic products, dielectric capacitors urgently need to be miniaturized and light weight for energy storage. The NaNbO₃-based lead-free antiferroelectric ceramic is an outstanding choice due to its high energy storage capacity, excellent charge and discharge performance, and a wide range of stability across various temperatures and frequencies. This study presents a new lead-free antiferroelectric ceramic (1 − x)NaNbO₃-x(Bi_0.2La_0.2Y_0.2Dy_0.2Tb_0.2)(Mg_0.5Hf_0.5)O₃ [(1 − x)NN-xBLYDTMH, x = 0.00, 0.05, 0.10, 0.15], which was synthesized via conventional solid-state reactions. The impedance analysis shows that introducing BLYDTMH could enhance the activation energies of the grain boundary, which is vital for the breakdown strength (E_b) of the ceramics. With the incorporation of BLYDTMH, the antiferroelectric phase is stabilized, and 0.90NN-0.10BLYDTMH shows a high breakdown strength. The ceramic exhibits the most satisfactory energy-storage properties, with a recoverable energy storage density of approximately 6.1 J cm⁻³ at an electric field of 670 kV cm⁻¹, at x = 0.10. And extremely short charge–discharge time (t_0.9 < 100 ns) remains at the nanosecond level, demonstrating significant potential for high-power pulsed capacitor applications. The strategy would offer a new approach to designing antiferroelectric materials suitable for various material systems used in energy storage capacitors.