多孔钛酸锶钡的制备及在复合材料中的应用

发布时间：2018-02-27 23:43

  本文关键词： 多孔Ba_(0.6)Sr_(0.4)TiO_3粉体 Ba_(0.6)Sr_(0.4)TiO_3/PVDF复合材料 介电常数 击穿场强 储能密度　出处：《北京化工大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文首先通过直接沉淀法制备了在室温下处于顺电相的钛酸锶钡BaxSr1-xTiO3 (x=0.2、0.3、0.5和0.6)纳米粉体；借助液相浇铸法制备成BaxS1-xTiO3/PVDF系列复合材料,对其性能测试发现Ba0.6Sr0.4TiO3的纳米粉体制备的复合材料具有高的材料储能密度。将该粉体作为原料,采用溶胶-凝胶法在其表面上包覆了同质的多孔Ba0.6Sr0.4TiO3层,研究了Ba0.6Sr0.4TiO3多孔包覆层与被包覆粉体的比例、造孔剂P123和反应温度对制备多孔粉体的影响,通过测量多孔Ba0.6Sr0.4TiO3粉体与PVDF复合制备Ba0.6Sr0.4TiO3/PVDF的电性能,并通过电滞回线测量分析了添加多孔粉体对复合材料储能密度提高的机制。采用直接沉淀法可以制备出立方相,形貌为球形的50nm BaxSr1-xTiO3粉体(x=0.2、0.3、0.5和0.6)。在1 kHz下,当BaxSr1-xTiO3粉体的添加比例为7 vol%时,BaxSr1-xTiO3/PVDF复合材料的介电常数均在14左右,其中Ba0.6Sr0.4TiO3/PVDF复合材料击穿场强为219.24 kV·mm-1,根据测量的电滞回线计算的储能密度,达到2.91 J·cm3,为纯PVDF储能密度的1.68倍。采用溶胶-凝胶法在溶胶生成温度为65℃、造孔剂P123用量与包覆层粉体的比例为0.1、包覆层与所包覆粉体的比例为2：1的条件下可以生成同质多孔Ba0.6Sr0.4TiO3。多孔Ba0.6Sr0.4TiO3粉体的添加量为7 vo1%时,制备的Ba0.6Sr0.4TiO3/PVDF复合材料的介电常数为15,击穿场强达到289.64 kV·mm-1,根据复合材料的电滞回线可计算出储能密度为3.70J·Cm-3,是纯PVDF储能密度的2.14倍；进一步提高复合材料中Ba0.6Sr0.4TiO3粉体的添加比例时,复合材料的介电常数虽有所提高,但是击穿场强和储能密度均有所下降。多孔Ba0.6Sr0.4TiO3粉体比表面的增加能够使聚合物产生一定的拉伸,导致晶格位错,从而捕获更多的电子使得击穿场强增加,且粉体的顺电性可以降低材料的剩余极化强度,进而提高复合材料的储能密度。
[Abstract]:In this paper, the nanocrystalline powders of barium strontium titanate (BaxSr1-xTiO3) and barium strontium titanate (BaxSr1-xTiO3) at room temperature were prepared by direct precipitation method, and BaxS1-xTiO3/PVDF series composites were prepared by liquid phase casting. It was found that the composite prepared by nano-powder of Ba0.6Sr0.4TiO3 had high energy storage density. The composite was coated with homogeneous porous Ba0.6Sr0.4TiO3 layer on the surface by sol-gel method. The effects of the ratio of porous coating layer of Ba0.6Sr0.4TiO3 and coated powder, the pore-making agent P123 and reaction temperature on the preparation of porous powder were studied. The electrical properties of Ba0.6Sr0.4TiO3/PVDF prepared by composite of porous Ba0.6Sr0.4TiO3 powder and PVDF were measured. The mechanism of adding porous powder to increase the energy storage density of composites was analyzed by hysteretic loop measurement. The cubic phase of 50nm BaxSr1-xTiO3 powder with spherical morphology was prepared by direct precipitation method. The dielectric constant of BaxSr1-xTiO3 / PVDF composites is about 14 when the addition ratio of BaxSr1-xTiO3 powder is 7 vol%, and the breakdown field strength of Ba0.6Sr0.4TiO3/PVDF composites is 219.24 kV 路mm-1.The energy density calculated from the measured hysteresis loop is used to calculate the energy storage density of BaxSr1-xTiO3 / PVDF composites, and the dielectric constant of BaxSr1-xTiO3 / PVDF composites is about 14. The energy density of pure PVDF was 1.68 times that of pure PVDF. The sol-gel method was used at 65 鈩，

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