Energy storage properties of BNT-BT based solid solution

The phase structure, microstructure, dielectric and energy storage properties of 0.85(0.92Bi 0.5 Na 0.5 TiO 3 -0.08BaTiO 3 )-0.15(Na 1−3x Bi x NbO 3 ) (BNTBT-NB x N) polycrystalline lead-free ceramics were systematically investigated. Dense and pore-free samples were prepared by conventional solid state reaction method. X-ray diffraction results indicated that the solid solubility of Bi in BNTBT-NB x N system lay at x=0.05∼0.07. Within the solid solubility, the first dielectric anomaly which located at temperature T s was depressed and shifted towards lower temperature with x increasing. As a consequence, the temperature stability of dielectric properties was largely improved, which demonstrated that BNTBT-NB x N ceramics were promising for high-temperature capacitor dielectrics. The ferroelectric properties analysis indicated that with the increase of x, the maximum polarization P m gradually reduced and the P-E loops became slant and slim. The optimum energy storage properties was obtained for x=0.05 with energy storage density W=1.29J/cm3 and energy storage efficiency η=76%.