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.