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In this study, the surface of solid oxide fuel cell electrolyte is decorated with different patterns by mesh pressing to improve the cell performance by increasing the surface area of electrolyte-electrode interfaces. Six various woven and unwoven metal meshes with different mesh gaps are considered in this respect. The patterned electrolyte surfaces are scanned by a profilometer to obtain the surface properties created by each mesh. Electrolyte supported cells are fabricated and tested to investigate the effects of electrolyte surface patterning on the cell performance. A cell with a flat electrolyte support is also manufactured and tested as a reference case. Impedance analyses are performed for a detailed examination beside microstructural observations via a scanning electron microscope. Under the same lamination conditions, woven meshes provide surface patterns with relatively higher average roughness values. Among the cases studied, the cell treated with a woven mesh having 0.57-mm wire diameter and 2-mm mesh gap on a side exhibits the highest maximum performance of 0.626 W cm À2 at 800 C, whereas that of the reference cell is only 0.320 W cm À2 , indicating that the performance of the reference cell can be almost doubled by the simple method suggested in this study. The impedance results show that the improvement in the cell performances is due to reduced electrode polarizations and ohmic resistance via mesh pressing, resulted from increased surface area of electrode-electrolyte interfaces and partially reduced electrolyte thickness as confirmed by microstructural observations, respectively.

Direct methanol fuel cells are devices that convert the chemical energy of methanol fuel having high energy density directly into electrical energy by electrochemical reactions. Methanol must be supplied to the fuel cell system as an aqueous solution to complete the reaction. Therefore, controlling and adjusting of methanol ratio in the methanol‐water mixture is critical for the continuity of direct methanol fuel cell performance. In this study, two fuel cell‐based electrochemical sensors are developed to adjust the amount of methanol in an aqueous solution in a direct methanol fuel cell. The experimental setup is prepared for the developed sensors and the effects of parameters, such as temperature, methanol flow rate, oxidizing effect, and methanol concentration, affecting the sensor performance are observed experimentally. It is observed that the experimental results obtained in the design without air input are more stable than that of the sensor working with air. However, in air‐independent design, the measurement value lost its stability after 2M concentration. The change in methanol flow rate did not cause any change in either sensor. High temperature and low methanol concentrations are found to be the main criteria for the best sensor performance.