High energy storage density and discharging efficiency in La3+/Nb5+-co-substituted (Bi0.5Na0.5)0.94Ba0.06TiO3 ceramics

In this work, [(Bi1-xLax)(0.5)Na-0.5](0.94)Ba-0.06(Ti1-5y/4Nby)O-3 ceramics have been developed by the dual-substitution of La3+ for Bi3+ and Nb5+ for Ti4+ and prepared by an ordinary sintering technique. All ceramics can be well-sintered at 1200 degrees C. The addition of La3+ and Nb5+ reduces the grain size and improve the dielectric breakdown strength of the ceramics; moreover, after the introduction of La3+ and Nb5+, the remanent polarization of the ceramics is significantly reduced, while the maximum polarization remains the same large value as that of the ceramic without the doping of La3+ and Nb5+. As a result, high energy storage density and discharge efficiency are achieved at x/y = 0.07/0.02, giving the large storage density of 1.83 J/cm(3) and high discharging efficiency of 70%. The present work presents a feasible strategy to develop energy storage materials based on perovskite ferroelectrics by the partial substitutions in the A and B sites.