Coupled ion redistribution and electronic breakdown in low-alkali boroaluminosilicate glass

Abstract

Dielectrics with high electrostatic energy storage must have exceptionally high dielectric breakdown strength at elevated temperatures. Another important consideration in designing a high performance dielectric is understanding the thickness and temperature dependence of breakdown strengths. Here, we develop a numerical model which assumes a coupled ionic redistribution and electronic breakdown is applied to predict the breakdown strength of low-alkali glass. The ionic charge transport of three likely charge carriers (Na+, H+/H3O+, Ba2+) was used to calculate the ionic depletion width in low-alkali boroaluminosilicate which can further be used for the breakdown modeling. This model predicts the breakdown strengths in the 108–109 V/m range and also accounts for the experimentally observed two distinct thickness dependent regions for breakdown. Moreover, the model successfully predicts the temperature dependent breakdown strength for low-alkali glass from room temperature up to 150 °C. This model showed that breakdown strengths were governed by minority charge carriers in the form of ionic transport (mostly sodium) in these glasses.

Glass Dielectrics in Extreme High‐Temperature Environment

“…Previous experimental and theoretical modeling studies have shown similar trends in the temperature‐dependent breakdown strength up to 150°C and Fig. shows a continuing trend up to temperatures of 400°C . The primary breakdown mechanism involves the formation of a high electric field region that is created by the depletion of mobile sodium ions .…”

“…2 shows a continuing trend up to temperatures of 400°C. 14 The primary breakdown mechanism involves the formation of a high electric field region that is created by the depletion of mobile sodium ions. 15 The increased mobility of the sodium ion coupled to thermally activated electron transport contributes to thickness and temperature-dependent break down.…”

“…15 The increased mobility of the sodium ion coupled to thermally activated electron transport contributes to thickness and temperature-dependent break down. 14 Figure 3 shows the relative permittivity (a) and dielectric loss (b) of OA10G glass (10 lm), PEI (12.5 lm), Kapton (7.5 lm), and PEEK (11.5 lm) as a function of temperature at 1 KHz. Compared with polymers, low-alkali aluminoborosilicate glass has higher dielectric constant and comparable dissipation factor.…”