Enhanced optical transmittance and energy-storage performance in NaNbO3-modified Bi0.5Na0.5TiO3 ceramics

Dielectric ceramics with both excellent energy storage and optical transmittance have attracted much attention in recent years. However, the transparent Pb-free energy-storage ceramics were rare reported. In this work, we prepared transparent relaxor ferroelectric ceramics (1 - x)Bi0.5Na0.5TiO3-xNaNbO(3) (BNT-xNN) by conventional solid-state reaction method. We find the NN-doping can enhance the polarization and breakdown strength of BNT by suppressing the grain growth and restrained the reduction of Ti4+ to Ti3+. As a result, a high recoverable energy-storage density of 5.14 J/cm(3) and its energy efficiency of 79.65% are achieved in BNT-0.5NN ceramic at 286 kV/cm. Furthermore, NN-doping can promote the densification to improve the optical transmittance of BNT, rising from similar to 26% (x = 0.2) to similar to 32% (x = 0.5) in the visible light region. These characteristics demonstrate the potential application of BNT-xNN as transparent energy-storage dielectric ceramics.