Effect of SiO2 Films with Different Thickness Deposited on Copper Electrode Surface for Insulation Properties of Propylene Carbonate

In this work, 100, 200, and 400 nm SiO 2 films are deposited on the electrode surface by magnetron sputtering, and the effect of film thickness on the insulation performance of propylene carbonate is studied. We use the Weibull distribution to calculate the breakdown voltage of propylene carbonate under different conditions. Space charge distribution of the liquid is measured based on the Kerr effect. Test results show that the breakdown voltage of propylene carbonate increases from 8.4 to 18.7% with increasing film thickness compared with the case where the SiO 2 film is not deposited. Bipolar injection mode of space charge is not affected by the increase of SiO 2 film thickness, but the amount of space charge injection is significantly reduced. The thicker the SiO 2 film deposited on the electrode surface, the higher the ratio of increasing the breakdown voltage of propylene carbonate, but the smaller the magnitude of the increase.