中文摘要：

选用金属Ni和Ag纳米颗粒作为导体相，采用共混法分别制备了击穿场强较高的Ni—BaTiO2／聚偏氟乙烯（Ni—BaTiO2／PVDF）和Ag—BaTiO2／PVDF三相复合材料。研究了导体相Ni和Ag添加量、粒径及导体种类对复合材料击穿场强的影响，发现Ni—BaTiO2／PVDF和Ag—BaTiO2／PVDF三相复合材料的击穿场强均随导体添加量的增加呈现先升高后降低的趋势，且在适宜的导体添加量下复合材料均表现出高于未添加导体相的BaTiO2／PVDF两相复合材料的击穿场强；添加同类导体Ni时，Ni粒径越小，三相复合材料的击穿场强提高越明显；导体添加量与粒径均相同时，Ni—BaTiO2／PVDF复合材料的击穿场强较高，当粒径50nm的Ni添加量为体积分数1．90％时，其击穿场强可达200kV／mm，储能密度比BaTiO2／PVDF两相复合材料提高4倍。这些结果可用库仑阻塞效应很好地解释。

英文摘要：

The Ni - BaTiOa/polyvinylidene fluoride （Ni - BaTiO3/PVDF） and Ag - BaTiOa/PVDF three component composites were prepared to improve the breakdown strength of the composites, in which Ni and Ag metal nano-particles were used as the third phase. The effects of addition, particle size and type of metals on the breakdown strengths of the composites were studied. The experimental resuhs show that all breakdown strengths of Ni - BaTiO3/PVDF and Ag - BaTiO3/PVDF three-component composites increase firstly and then decline with the increase of Ni or Ag addition. And all composites give comparative dielectric constants than those without metals addition and each has maximum breakdown strength over the range of metal addition. For same type metal of Ni, addition with smaller size of Ni is better for enhancing the breakdown strength of the composites. Moreover with the same particle size and addition, Ni- BaTiOa/PVDF composites show better breakdown performance. The breakdown strength of Ni（50 nm）- BaTiOa/PVDF nanocomposite with 1. 90% volume fraction of Ni reaches up to 200 kV/mm and its energy density is about five times of BaTiO3/PVDF composite. The Coulomb blockade effect is employed to explain the dielectric breakdown strengths under high electric field of such kind of composties.