In-situ temperature sensing of SOFC during anode reduction and cell operations using a multi-junction thermocouple network

Understanding in-situ temperature distribution of a SOFC stack while in operation is very important for its performance and degradation studies. The available efforts in literature are incapable of measuring the temperature of electrodes. The proposed multi-junction thermocouple network, which requires only 2N thermoelements for N² measuring points, can measure temperature directly from electrodes. A multi-junction thermocouple network having 9 measuring points was fabricated using K-type thermocouple wires (φ 0.5mm) for an in-situ measurement of the temperature distribution on a cathode (50mmx50mm, NextCell-5). The measurements were performed during an anode reduction process and during a normal cell operation while the air/fuel ratio varies. The gas temperature was measured simultaneously using a commercial K-type thermocouple from 7 mm adjacent to the cathode. The monitored cathode temperature via the in-situ sensors was directly correlated with the cell's OCV whilst the commercial thermocouple 7mm adjacent to the electrode showed a dull change to them.