B1.2 Failure Analysis of Overloaded Coulometric Hydrogen Sensor
- SMSI 2021
2021-05-03 - 2021-05-06
- SMSI 2021 - Sensors and Instrumentation
- B1 Gas Sensors I
- A. Graff, W. Münchgesang, F. Altmann - Fraunhofer Institute IMWS, 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)
- 105 - 106
An irreversible degradation of a coulometric hydrogen sensor is observed after operation at high electrical load. Microstructural investigations were performed on the YSZ ceramic tube of the sensor with outer and inner electrodes to find the root causes for the degradation. Local color changes (blackening) were observed caused by the reduction of the YSZ by oxygen diffusion at grain boundaries under chemical and electrical potential. Crack formation and phase transitions in the YSZ ceramic from cubic to monoclinic can explain the irreversible degradation of the solid electrolyte sensor.