Enhanced breakdown strength via a codoping strategy and tape-casting technique: An approach for excellent energy storage performance in lead-free AgNbO3-based antiferroelectrics

Lead-free AgNbO3-based antiferroelectric (AFE) ceramics have attracted increasing interest owing to their environmentally friendly nature and excellent potential in energy storage devices. However, the poor breakdown strength (BDS) of AgNbO3 limits its practical application. Herein, the Mn/Sm-codoing strategy and the tape- casting technique were utilized to improve the BDS of AgNbO3-based ceramics to 320 kV cm- 1 , which is almost 1.8 and 1.6 times greater than that of doped AgNbO3 prepared by solid-state reaction and that of pure AgNbO3 prepared by the tape-casting method, respectively. The relatively high BDS is attributed to the improved density, the grain size reduction and the decrease of concentration of oxygen vacancies. As a result, a high energy storage density of 5.18 J cm- 3 with an efficiency of 73.3 % were observed. Our research enriches the fabrication strategy of lead-free AFE ceramics with high BDS and contributes to the applications of AFE-based energy storage devices.