High-voltage gradient ZnO varistors have gradually been applied to overvoltage protection of power equipment due to their ability to withstand higher working voltages. However

AC aging is a practical problem faced by high-voltage gradient varistors in ultra-high voltage applications. Ag+-doped ZnO is effective in improving the performance of varistors. In order to determine the optimal doping concentration required by the improvement of long-term stability of varistors

the microstructure

macroscopic electrical properties and barrier potential of ZnO varistors doped with different concentrations of silver oxides are studied

and the mechanism for improving anti-aging ability by Ag+ is theoretically explained. The research results show that when the doping amount of silver oxide is 0.011%

the optimal anti-aging performance of high-voltage gradient ZnO varistors can be achieved.