Designing silver niobate-based relaxor antiferroelectrics for ultrahigh energy storage performance
Zhengdong Hu, Zhen Liu, Bing Han, Haonan Peng, Kai Dai, Zequan Xu, Zhengqian Fu, Zhigao Hu, Genshui Wang
Abstract
AgNbO<sub>3</sub> (AN) and modified AgNbO<sub>3</sub> 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 (<i>W</i><sub>rec</sub>) and efficiency (<i>η</i>) are still difficult to realize. Herein, we innovatively constructed a AgNbO<sub>3</sub>–NaNbO<sub>3</sub>–(Sr<sub>0.7</sub>Bi<sub>0.2</sub>)TiO<sub>3</sub> (AN–NN–SBT) ternary solid solution to achieve a relaxor AFE in AgNbO<sub>3</sub>-based materials. The coexistence of antiferroelectric (M<sub>3</sub>) and paraelectric (O) phases in 0.8(0.7AgNbO<sub>3</sub>–0.3NaNbO<sub>3</sub>)–0.2(Sr<sub>0.7</sub>Bi<sub>0.2</sub>)TiO<sub>3</sub> confirms the successful realization of a relaxor AFE, attributed to multiple ion occupation at the A/B sites. Consequently, a high <i>W</i><sub>rec</sub> of 7.53 J·cm<sup>−3</sup> and <i>η</i> 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<sup>−3</sup>) and fast discharge speed (41.4 ns) are also demonstrated for the AgNbO<sub>3</sub>-based relaxor AFE. This work presents a promising energy storage AgNbO<sub>3</sub>-based ternary solid solution and proposes a novel strategy for AgNbO<sub>3</sub>-based energy storage via the design of relaxor AFE materials.