(1. 中南大学 粉末冶金国家重点实验室，长沙 410083；
2. 四川大学 匹兹堡学院，成都 610207)
摘 要: 分别采用固相法和溶胶-退火法合成了AgNbO3颗粒(分别定义为AgNO3-1和AgNO3-2)，使用多巴胺对该颗粒进行表面修饰后，再以此为填充物，与P(VDF-HFP)聚合物基体复合，制备不同AgNbO3填料比的(Dop@AgNbO3)-P(VDF-HFP)复合材料。采用X射线衍射分析仪(XRD)、扫描电子显微镜(SEM)、红外光谱仪、阻抗分析仪和铁电工作站等表征了AgNbO3颗粒及其复合物的物相、微观结构，探究填料合成工艺及含量对复合材料介电及储能性能的影响规律。结果表明：同一种填料合成工艺下制备的(Dop@AgNbO3)- P(VDF-HFP)复合物，随着填料比增加，能量密度呈现先增加后减小的趋势，在填料比6%(体积分数)时获得最高储能密度。此外，在相同的填料比下，基于溶胶-退火法合成的AgNbO3颗粒由于粒径较小，粒度分布较窄，比表面积较大，使得(Dop@AgNbO3-2)-P(VDF-HFP)复合物的整体介电和储能性能优于(Dop@AgNbO3-1)-P(VDF-HFP)复合材料。例如，6% (Dop@AgNbO3-2)-P(VDF-HFP)复合材料在1 kHz时的介电常数为17.6，介电损耗小于0.05；在电场80 kV/mm下的有效能量密度和效率分别为0.46 J/cm3和71.35%。
关键字: AgNbO3；介电复合材料；P(VDF-HFP)；介电常数；能量密度
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Pittsburgh Instiute, Sichuan University, Chengdu 610207, China）
Abstract:The AgNbO3 micro-nano particles synthetized by traditional solid-state method (AgNbO3-1) and sol-gel method (AgNbO3-2) were modified with dopamine and then filled with P(VDF-HFP) matrix to prepare Dop@AgNbO3-P(VDF-HFP) nanocomposites. X-ray diffraction analyzer (XRD), scanning electron microscope (SEM), infrared spectrometer, impedance and ferroelectric analyzer were used to characterize the phase and microstructure of AgNbO3 particles and their composites. The influences of synthesis process and loading of AgNbO3 fillers on the dielectric and energy storage performance of composites were explored. The results show that when the Dop@AgNbO3)-P(VDF-HFP) composite is prepared under the same AgNbO3 particles synthesis process, the energy density first increases and then decreases with increasing the filler loading, and the highest energy density is obtained at 6% AgNbO3 filler loading. In addition, at the same fillers loading, (Dop@AgNbO3-2)-P(VDF-HFP) composites show superior dielectric and energy storage performance compared with (Dop@AgNbO3-1)-P(VDF-HFP) composites due to a smaller particle size, narrower particle size distribution and larger specific surface area of AgNbO3-2 particles. For instance, at 1k Hz, the dielectric constant and loss of 6% (Dop@AgNbO3-2)-P(VDF-HFP) composite are 17.6 and 0.05, respectively. At the electric field of 80 kV/mm, the discharged energy density and efficiency are 0.46 J/cm3 and 71.35%, respectively.
Key words: AgNbO3; dielectric composites; P(VDF-HFP); dielectric constant; energy density
