中文摘要：

采用固相法制备了（0.94-x）Bi（0.5）Na（0.5）TiO3-x（K（0.9）Na（0.1））NbO3-0.06BaTiO3（（0.94-x）BNT-x KNN-0.06BT,x=0,0.03,0.06,0.09,0.12,0.15）无铅储能陶瓷,系统研究了（K（0.9）Na（0.1））NbO3（KNN）添加量x对陶瓷相结构、微观结构和电储能特性的影响。X射线衍射（XRD）分析结果表明：当x≤0.03时,陶瓷为纯立方钙钛矿结构,而当x≥0.06时,出现第二相。扫描电子显微镜（SEM）结果显示各陶瓷具有高的致密度。采用HP4294精密阻抗分析仪测试了陶瓷的介电性能,采用美国Radiant铁电分析仪测试了陶瓷的电滞回线并计算了其储能密度和能量效率。结果表明在1120℃烧结温度下制备的（0.94-x）BNT-x KNN-0.06BT陶瓷,当x=0.03时,陶瓷具有优异的性能：相对介电常数ε（33）T/ε0=2440,介电损耗tanδ=5.1%,在外加电场90 k V/cm条件下,其有效储能密度γ达到1.43 J/cm3,且具有较高的能量效率η=72.5%,表明该陶瓷可应用在高压储能陶瓷电容器中。

英文摘要：

（0.94-x）Bi（0.5）Na（0.5）TiO3-x（K（0.9）Na（0.1））NbO3-0.06BaTiO3（（0.94-x）BNT-x KNN-0.06 BT, x=0,0.01,0.02,0.03,0.04,0.05） lead-free energy storage ceramics were prepared by a solid state reaction method. The effect of（K（0.9）Na（0.1））NbO3（KNN） doping amount x on the crystal structure, microstructure and electrical energy storage characteristics of the ceramics was investigated. X-ray diffraction（XRD） analysis showed that the ceramic had a pure cubic perovskite structure when x ≤ 0.03, while the secondary phase occurred when x ≥ 0.06. Scanning electron microscopy（SEM） analysis showed that all the ceramics possessed high bulk density. The dielectric properties of the ceramics were measured by a HP4294 precision impedance analyzer. The ferroelectric hysteresis P-E loops of the ceramics were measured by a Radiant ferroelectric analyzer system, and the energy storage density and efficiency were calculated according to the P-E loops. For（0.94-x）BNT-x KNN-0.06 BT ceramics with x=0.03 sintered at 1120 ℃, optimized properties were obtained as follows： relative dielectric constant ε（33）T/ε0=2440, dielectric loss tanδ=5.1%. Under an applied electric field of 90 k V/cm, the energy storage density γ reached a high value of 1.43 J/cm3 with an energy efficiency η=72.5%, indicating its application for high voltage energy storage ceramic capacitors.