Title: Effect of manganese doping on electrical performance and impulse aging properties of ZnO varistor

Authors: Zhengzheng Fu; Zongxi Zhang; Songhai Fan; Xianghang Bu; Zhihang Xue; Yue Yin

Addresses: State Grid Sichuan Electric Power Research Institute, No. 16, Jinhui West Second Street, High-Tech Zone, Chengdu 610041, China ' State Grid Sichuan Electric Power Research Institute, No. 16, Jinhui West Second Street, High-Tech Zone, Chengdu 610041, China ' State Grid Sichuan Electric Power Research Institute, No. 16, Jinhui West Second Street, High-Tech Zone, Chengdu 610041, China ' State Grid Sichuan Electric Power Research Institute, No. 16, Jinhui West Second Street, High-Tech Zone, Chengdu 610041, China ' State Grid Sichuan Electric Power Research Institute, No. 16, Jinhui West Second Street, High-Tech Zone, Chengdu 610041, China ' College of Electrical Engineering, Sichuan University, No. 24, Section 1, South First Ring Road, Wuhou District, Chengdu 610065, China

Abstract: In this study, we assessed the impact of varying concentrations of MnO₂ doping on the electrical characteristics of ZnO varistors, both before and after 100 times of 8/20 μs impulse current aging. The findings revealed that the MnO₂ content of less than 1 mol% is mainly solidified in the grain, which increases the donor density, decreases the barrier height and decreases the nonlinear coefficient. However, when MnO₂ doping content above 1 mol%, the Mn⁴⁺ begin to segregate at the grain boundary, increasing the surface state density and barrier height, and increasing the nonlinear coefficient. This segregation process also hinders migration of zinc ions in the depletion layer, thereby enhancing the impulse aging properties of the varistor. After 100 times lightning impulse currents, the varistor doped 1.5 mol% MnO₂ showed the best aging performance. This study provides an important theoretical basis for improving the lightning impulse aging performance of ZnO varistors.

Keywords: ZnO varistor; MnO₂; impulse aging; V-I characteristic.

DOI: 10.1504/IJMMP.2025.150864

International Journal of Microstructure and Materials Properties, 2025 Vol.18 No.3, pp.213 - 223

Received: 27 Mar 2024
Accepted: 12 Dec 2024
Published online: 24 Dec 2025 *

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