Enhanced comprehensive energy storage properties in NaNbO3-based relaxor antiferroelectric via MnO2 modification

The MnO 2 is generally used as a sintering aid to improve sintering quality and breakdown electric field of ceramic capacitors, however, few studies were conducted to provide a guidance for the appropriate amount of MnO 2 additive that should be added. In this work, various contents of MnO 2 were added into 0.84NaNbO 3 -0.16CaTiO 3 to systematically study its effect. The phase structure, dielectric behavior, microstructure, and so forth demonstrate that an appropriate MnO 2 additive can stabilize antiferroelectric phase, optimize microstructure, and increase breakdown electric field. The 1.5 mol% MnO 2 doped sample exhibits excellent comprehensive energy storage performance with an ultrahigh recoverable energy storage density of 5.8 J/cm 3 , good efficiency of 81%, splendid frequency and temperature stabilities, and outstanding charge-discharge properties. This work provides a promising energy storage material and a design concept based on MnO 2 modification, which will contribute to the development and application of NN-based dielectric materials.