Exploration of Electric-Field Effects in Solid State Ionic Devices

Abstract

This work explored the effect of localized electric fields on the performance of solid-state ionic devices. This was accomplished through the use of field electrodes, which created an electric field without leaking charge to the electrochemical cell. This is a significant distinction from fields generated with a direct bias including electrochemically promoted or NEMCA (Non-Faradaic Electrochemically Modified Catalytic Activity) enhanced cells. To investigate these field effects, we utilized a potentiometric gas sensor as a model device. We found that indirectly generated fields can improve device performance. For example, we have seen more than a 20X increase in NOx sensitivity. In this work, we compare planar sensor results, core and valence level photoelectron spectroscopy measurements, and other past surface science evidence to explore the origin of these effects. Our method for actively controlling ionic device performance can potentially be applied to gas sensors, fuel cells, gas separation membranes, and chemical reactors.