B1.4 Microstructural Investigations of Blackening in YSZ Sensors for Hydrogen Coulometry
- SMSI 2020
(did not take place because of Covid-19 virus pandemic)
- SMSI 2020 - Sensors and Instrumentation
- B1 Hydrogen Sensors
- 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)
- 99 - 100
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.