Study of the Effect of Ca on the Electrical Properties of SnO₂ Varistor Based on the Voronoi Model

The tin oxide (SnO₂ ) varistor is a most promising pressure-sensitive material. To improve its stability in practical operation, this paper constructs a numerical simulation model of the varistor based on the Voronoi network model in computational materials science, and investigates the effect of calcium doping on its microstructure and comprehensive electrical properties. The experimental and computational results showed that the best electrical properties were obtained when the Ca doping concentration was 0.04 mol%, with an E_1mA of 693 V/mm, J_L of 12.3 µA/cm², and an ɑ of 26.97. Finally, an AC accelerated aging test was performed on a sample doped with 0.04 mol% Ca (0.9 E_1mA/135 °C/160 h), and the minimum value of K_t was 0.316. This study provides an experimental basis for the development of SnO₂ varistors with high stability and economy.