B1.4 Microstructural Investigations of Blackening in YSZ Sensors for Hydrogen Coulometry

Event
SMSI 2020
-
(did not take place because of Covid-19 virus pandemic)
Band
SMSI 2020 - Sensors and Instrumentation
Chapter
B1 Hydrogen Sensors
Author(s)
A. Graff, W. Münchgesang, F. Altmann - Fraunhofer Institute for Microstructure of Materials and Systems, Halle (Germany), C. Himcinschi, T. Köhler - Technische Universität Bergakademie Freiberg, Freiberg (Germany), P. Sood, J. Zosel, M. Mertig - Kurt-Schwabe-Institut für Mess- und Sensortechnik Meinsberg e.V., Waldheim (Germany)
Pages
99 - 100
DOI
10.5162/SMSI2020/B1.4
ISBN
978-3-9819376-2-6
Price
free

Abstract

A detailed microstructural analysis of a coulometric hydrogen sensor after operation at high electrical load is presented. The sensor is based on YSZ ceramic tube with outer and inner electrodes. Oxygen diffusion at grain boundaries under chemical and electrical potential leads to color changes (blackening), crack formation at the grain boundaries and phase transitions in the YSZ ceramic from cubic to monocline. These findings can explain an irreversible degradation mechanism of the solid electrolyte sensor.

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