Designing silver niobate-based relaxor antiferroelectrics for ultrahigh energy storage performance

Abstract

AgNbO3 (AN) and modified AgNbO3 have been extensively investigated as promising lead-free antiferroelectric (AFE) energy storage materials. Previous studies have focused mainly on the use of an ion dopant at the A/B site to obtain a stabilized AFE phase; however, simultaneous improvements in the recoverable energy storage density (Wrec) and efficiency (η) are still difficult to realize. Herein, we innovatively constructed a AgNbO3–NaNbO3–(Sr0.7Bi0.2)TiO3 (AN–NN–SBT) ternary solid solution to achieve a relaxor AFE in AgNbO3-based materials. The coexistence of antiferroelectric (M3) and paraelectric (O) phases in 0.8(0.7AgNbO3–0.3NaNbO3)–0.2(Sr0.7Bi0.2)TiO3 confirms the successful realization of a relaxor AFE, attributed to multiple ion occupation at the A/B sites. Consequently, a high Wrec of 7.53 J·cm−3 and η of 74.0% are acquired, together with superior stability against various temperatures, frequencies, and cycling numbers. Furthermore, a high power density (298.7 MW·cm−3) and fast discharge speed (41.4 ns) are also demonstrated for the AgNbO3-based relaxor AFE. This work presents a promising energy storage AgNbO3-based ternary solid solution and proposes a novel strategy for AgNbO3-based energy storage via the design of relaxor AFE materials.

Keywords

• agnbo3 (an)-based ceramics
• relaxor antiferroelectric (rafe)
• paraelectric (pe)
• energy storage performance