Thickness Effect of TiO2 Film Deposited on a Blade-Plate Electrode Surface on Breakdown Characteristics of Propylene Carbonate

Low-temperature plasma surface modification technology can help optimize the physical and chemical properties of materials. In this study, TiO
₂
films with thicknesses of approximately 100, 200, and 300 nm are prepared on an electrode surface using the magnetron sputtering method to explore the effect of film thickness on the breakdown characteristics of the liquid dielectric. The breakdown voltage of the liquid dielectric under a non-uniform electric field is determined using the Weibull distribution method. Based on the Kerr electro-optical effect, the changes in the spatial electric field along the symmetrical line of the blade-plate electrode gap are measured. The results show that compared to the undeposited state, the positive breakdown voltage of the liquid dielectric increases by 8.0%, 13.4%, and 15.9% corresponding to film thicknesses of 100, 200, and 300 nm, respectively, whereas the negative breakdown voltage increases by only 2.3%, 4.4%, and 5.7%. The TiO
₂
film on the electrode surface has a greater impact on the increase in the breakdown voltage of the positive polarity, resulting in a decrease in the difference between the breakdown voltage of the positive and negative polarity. Therefore, it has great potential in improving the insulation performance of liquid dielectrics under uneven electric fields.