Realizing Superior Energy Storage Performance and Ultrafast Discharge Rate in NaNbO<sub>3</sub>-Based Ceramics by Multiscale Manipulation
Xiao Zhai, Mengdi Lu, Juan Du, Wei Li, Jigong Hao, Weijie Kuai, Zhigang Gai, Minglei Zhao, Limei Zheng
Abstract
Dielectric capacitors exhibit great promise for use in advanced energy storage devices. Nevertheless, realizing a large energy storage density ( W rec ) and high efficiency (η) remains an arduous challenge. In this work, a multiscale manipulation strategy was employed by integrating polar-nanoregions (PNRs) regulation at the nanoscale and grain-structure regulation at the microscale to enhance energy storage performance of NaNbO 3 -based ceramics. The incorporation of (Bi 0.5 Na 0.5 ) 0.7 Sr 0.3 TiO 3 (BNST) into (Na 0.94 La 0.06 )(Nb 0.88 Zr 0.12 )O 3 (NLNZ) ceramics induces a high amount of PNRs at the nanoscale, thereby giving rise to a high η and an ultrafast discharge rate. In addition, at the microscale, the decreased grain size and dense structure enhance the resistivity as well as the activation energy of the ceramics, thus leading to a large breakdown electric field ( E b ) and consequently an enhanced W rec . At last, the optimal energy storage performance ( W rec ∼ 9.3 J/cm 3, η ∼ 82.4% at E b ∼ 920 kV/cm) was realized in the 0.80NLNZ–0.20BNST ceramic through the multiscale manipulation. Furthermore, the 0.80NLNZ–0.20BNST ceramic also demonstrates excellent stabilities under varying frequency (1–500 Hz), temperature (20–160 °C), and cycling (1–10 6 cycles) as well as outstanding charge/discharge performances (power density P D ∼ 407 MW/cm 3, current density C D ∼ 1659 A/cm 2, and discharge rate t 0.9 ∼ 13 ns). These results suggest that the 0.80NLNT–0.20BNST ceramic exhibits a significant energy storage application potential.