界面改善对P（VDF-co-CTFE）/BST复合材料介电和储能性能影响

摘要

High-activity barium strontium titanate（BST） nanoparticles with diameter of 50nm were synthesized via sol-gel method.The BST particles were surface modified with a silane coupling agent（KH550）.After that,the BST nanoparticles were then compounded with poly（vinylidene fluoride-co-chlorotrifluoroethylene）（P（VDF-co-CTFE）） in 0-3 connecting form.Using solution casting method,P（VDF-co-CTFE） /BST nanocomposite thick films were prepared on quartz slides.And water-quenching experiments were finally performed on the composite thick films.XRD,TEM,TGA,and FE-SEM were used to characterize the BST particles and the obtained films.Results indicate that the interface of the BST nanoparticles has been effectively improved by surface modification with KH550.Compared with the nanocomposite films with uncoupled BST particles,the ones with KH550-coupled BST particles possess higher dielectric constant（〉33）,larger breakdown electric field（〉270MV/m）,and lower dielectric loss.Moreover,the surface modification is also helpful to improve the film saturation polarization（Ps）,and decrease the film remnant electric polarization（Pr）,thus finally enhancing the film electrical energy density（〉6.8J/cm3 for a film sample with BST of 10vol%）.The overall results indicate that the surface modification for polymer/ceramic compounds shows great potential in the field of high-energy storage devices.%用溶胶-凝胶法合成了钛酸锶钡（BaSrTiO3,BST）陶瓷,获得了粒径为50nm左右的高活性纳米陶瓷粉体,并通过硅烷偶联剂（KH550）进行了表面处理。将表面处理后的BST粉末与含氟铁电聚合物聚偏氟乙烯-三氟氯乙烯（P（VDF-co-CTFE））采用0-3方式进行了复合。然后通过溶液流延法在石英片上制备了P（VDF-co-CTFE）/BaSrTiO3复合材料厚膜,并进行了淬火处理。采用XRD、TEM、TGA和SEM表征了纳米陶瓷和复合材料形貌。结果表明KH550可以有效地作用于高介电常数BST陶瓷颗粒表面。KH550处理后的复合材料具有更大的介电常数（εr〉33）,更高耐电场强度（Eb〉270MV/m）和较低的损耗。界面处理同时可以有效提高复合材料的饱和极化强度（Ps）,降低剩余极化强度（Pr）,使其储能密度（Ue）达6.8J/cm3。总体结果表明,两相界面改善后的聚合物/陶瓷复合材料在高储能密度领域中具有广泛的应用前景。