An ultrahigh energy storage density in lead-free Na0.5Bi0.5TiO3-NaNbO3 based ceramics via multiple optimization strategies
Wenhan Zeng, Xiang Niu, Yuleng Jiang, Huanwei Liu, Zihao Xu, Xubing Lu, Mingtao Xu, Hongbin Lin, Houzhu He, Xiaobo Zhao, Yingbang Yao, Tao Tao, Bo Liang, Sheng‐Guo Lu
Abstract
Currently, dielectric capacitors with superior charge-discharge performance, long lifetime, and high power density are drawing increasing attention, especially for lead-free ferroelectrics due to their environmental friendliness, multi-functional applications and excellent energy storage properties. In this work, lead-free relaxor ferroelectric Sr(Mg 1/3 Ta 2/3 )O 3 (SMT)-modified Na 0.5 Bi 0.5 TiO 3 NaNbO 3 (NBT-NN) bulk and thick film ceramics were prepared via solid-state reaction and tape-casting approaches, respectively, and their energy storage characteristics were tailored via multiple optimization strategies. A high recoverable energy density (∼5.20 J/cm 3 ) and efficiency (∼82.24 %) at 380 kV/cm were obtained for bulk ceramics. In addition, an ultrahigh recoverable energy density (∼17.24 J/cm 3 ) with a high efficiency (∼82.02 %) at 1200 kV/cm was obtained in thick film ceramics, which are attributed to the improvement of dielectric breakdown strength (DBS) and the transformation to the relaxor ferroelectrics. Moreover, the excellent temperature (30–130 °C) and frequency (0.5–500 Hz) stabilities were also obtained at 600 kV/cm.