Dielectric Behavior And Breakdown Properties Of Calcium Titanate Ceramic Particles / PVDF Composites

Polyvinylidene fluoride(PVDF)is widely used in electrical equipment.The performance of PVDF can be improved by adding high dielectric ceramic materials.As a kind of ceramic material with huge dielectric constant,Copper Calcium Titanate can effectively improve dielectric properties of dielectric.However,as ceramic particles,it will have a negative effect on the breakdown field strength of the dielectric after adding in.In order to improve the breakdown performance of CCTO/PVDF composites,surface dopamine coverage was performed on CCTO.Different proportions of CCTO and Dopa@CCTO were added to the PVDF matrix to prepare CCTO/PVDF and Dopa@CCTO/PVDF composite films with different volume fractions.The structure of CCTO,Dopa@CCTO,CCTO/PVDF and Dopa@CCTO/PVDF were characterized by scanning electron microscopy and infrared spectroscopy.The dielectric properties of CCTO/PVDF and Dopa@CCTO/PVDF composite films were tested respectively.The data showed that with the increase of CCTO and Dopa@CCTO,The dielectric constants of CCTO/PVDF composite films and Dopa@CCTO/PVDF composite films were improved.Comparing the breakdown field strength of CCTO/PVDF and Dopa@CCTO/PVDF composite films at the same volume fraction,it was found that the penetration field strength of the composite material after dopamine modification was significantly improved.The breakdown experiment of the obtained CCTO/PVDF composite film showed that: with the increase of CCTO addition,the direct flow through field strength of CCTO/PVDF showed a declining trend.In addition,the breakdown field strength of all proportions of CCTO/PVDF is lower than that of pure PVDF.The breakdown experiment on the Dopa@CCTO/PVDF composite film showed that: with the increase of the addition of Dopa@CCTO,the direct flow penetration field strength of the composite material showed a declining trend,and it was lower than that of pure PVDF.Comparing the breakdown field strength of CCTO/PVDF and Dopa@CCTO/PVDF composite films at the same volume fraction,it was found that the penetration field strength of the composite material after dopamine modification was significantly improved.It is very important for the development of energy storage devices to improve the breakdown field under the premise of ensuring the dielectric properties of composite materials.