We present single‐step‐co‐sintering manufacture of a planar single‐chamber solid oxide fuel cell (SC‐SOFC) with porous multilayer structures consisting of NiO/CGO, CGO and CGO‐LSCF as anode, electrolyte, and cathode, respectively. Their green tapes were casted with 20 μm thickness and stacked into layers of anode, electrolyte, and cathode (10:2:2), then hot‐pressed at 2 MPa and 60°C for 5 minutes (deemed optimal). Subsequently, hot laminated layers were cut into 40 × 40 mm cells and co‐sintered up to 1200°C via different sintering profiles. Shrinkage behavior and curvature developments of cells were characterized, determining the best sintering profile. Hence, anode‐supported SC‐SOFCs were fabricated via a single‐step co‐sintering process, albeit with curvature formation at edges. Subsequently, anode thickness was increased to 800 μm and electrolyte reduced to 20 μm to obtain SOFCs with drastically reduced curvature with the help of a porous alumina cover plate.

Thermal management of SOFCs (solid oxide fuel cell) is important for helping to minimise high temperature-related performance losses and maximising cell/stack lifetime. Thin film sensor technology is proposed as an excellent candidate to measure the cell temperature during operation due to its negligible mass, minimal disturbance to normal operation and higher temporal and spatial resolutions. However, the effective application of such sensors in SOFC systems is a challenging endeavour and predicated on incorporating the external wire attachments to complete the electrical circuit. This is because of the high sensitivity of SOFC materials to any interference to operation, limited available space and harsh operating conditions. In this paper, a new concept of packaging external wire attachments to the thin film sensor is described to enable the integration of the sensor in the SOFC system. Temperature measurements have been monitored under OCV and operating condition with the thin film sensor directly from SOFC cathode surface via proposed spring-based wire connection, from room temperature to SOFC operating temperature. The impact of the parameters including contact resistance (Rc) between sensor pads and attached wire on monitored temperature has also been analysed with the contribution of conductive paste. High temporal and spatial resolutions have been obtained with the implemented sensor.

The fluorescence spectroscopy technique was used to measure the residual stress between the cathode and electrolyte of an anode supported planar single-chamber solid oxide fuel cell. The cell was made of (NiO-CGO) :(CGO) :(LSCF-CGO), as anode:electrolyte:cathode and the test was carried out after sintering at room temperature. The measured stress between these layers arises from the sintering stress caused by differential shrinkage from layers during sintering and the thermal expansion co-efficient mismatch between the layers during cooling. Therefore, the residual stress in the cathode and electrolyte layer of the cell due to co-efficient of thermal expansion mismatch during cooling was calculated analytically so as to find sintering stress. According to findings a maximum compressive residual stress of -1084 MPa occurred at the place contiguous to electrolyte layer. The estimated residual stresses in the cell’s cathode and electrolyte layer owing to CTE mismatch for the duration of cooling was calculated as -324 MPa and 15.96 MPa, respectfully. Furthermore, total mean residual compressive stress between cathode and electrolyte was obtained from fluorescence spectroscopy as -703.795. Thus, the main contribution of this residual stress is the stress growth during sintering (-395.755 MPa) due to different shrinkage behavior of adjacent layers.

In this work, a reverse trapezoidal cross-section channel shape for a single flow channel PEM fuel cell was examined with computational fluid dynamic (CFD) method. ANSYS Fluent was applied to solve electrochemical reactions, potential fields, mass, species, and energy transport equations. Species mass ratio, temperature distribution and relative humidity were obtained for the cell as well as the i-V and power density plots. The results were compared to two reference geometries with the commonly used square section shape for the channel. One reference geometry has the same channel width and height with the reverse trapezoidal cross-section channel while the other has the same cross-section area. The results indicate that the cell with reverse trapezoidal cross sectional flow channel shape has more than 32% higher power density than the cell with square cross-sectional flow channel shapes, but poor water management.