The effects of Mn²⁺ doping on energy storage properties of 0.94Bi_0.5Na_0.5TiO₃–0.06BaTiO₃ ceramics

The Mn²⁺-doped 0.94Bi_0.5Na_0.5Ti_(1−x)Mn_xO₃-0.06BaTiO₃ (BNTMx-BT, x = 0.00 ~ 0.06) system was prepared by the conventional solid-state method. The XPS results showed that some of the Mn²⁺ doped into the BNT-BT ceramics were transformed into higher valence states of Mn³⁺ and Mn⁴⁺, which led to an increase in the adsorbed oxygen content in the ceramics and a decrease in the concentration of the oxygen vacancies. Accordingly, the leakage current in the ceramics is steeply decreased by the doping of Mn²⁺. The dielectric temperature spectrum exhibited that the doping of Mn²⁺ weakened the T_s dielectric peak and caused the T_m peak to exhibit a more significantly frequency dispersion, which were conducive to the enhancement of the relaxation properties of the ceramics. The ceramics sintered at 1125 °C obtained a better storage performance at x = 0.03 (W_rec = 0.51 J/cm³, η = 39.74%).