Improving the energy storage performances of Bi(Ni0.5Ti0.5)O-3-added K0.5Na0.5NbO3-based ceramics

摘要

K0.5Na0.5NbO3 (KNN)-based ceramics are ideal alternatives to lead-containing ceramics because of their high maximum polarization and relatively large breakdown strength, however the low energy efficiency (eta) remains a constraint on application. In this work, a novel (1-x)K0.5Na0.5NbO3-xBi(Ni0.5Ti0.5)O-3 (1-x)KNN-xBNiT ceramics were designed and prepared using traditional solid state reaction method. An optimal recoverable energy storage density (W-rec) of 2.61 J/cm(3) accompanied by an ultrahigh eta of 82.6 was simultaneously achieved in 0.85KNN-0.15BNiT ceramic under 280 kV/cm. Furthermore, a favorable temperature and frequency stability (the variation of W-rec and < 3 over the range of 25-150 degrees C and 1-100 Hz) of energy storage performances (ESP) can be obtained. Meanwhile, 0.85KNN-0.15BNiT ceramic exhibits an outstanding power density (47.8 WM/cm(3)) and a fast discharge speed (t(0.9) = 46.9 ns) under 120 kV/cm. These results reflect that 0.85KNN-0.15BNiT ceramic is a deserved candidate for the application of high energy storage devices.