The geometries of flow fields have a strong impact on gas distribution in fuel cells. In the present work, a series of customized spiral flow fields were applied to high-temperature polymer electrolyte fuel cells. Pressure tests revealed that a flow crossover occurred in the spiral flow field under consideration, which was caused by the pressure difference between two adjacent channels. Electrochemical characterization indicated that the modified gas distribution compensated the O2 depletion along the channel and improved the supplement of O2 in the electrode, as well as the proton conductivity of the electrolyte. The best performances were obtained with a spiral flow field using a channel depth of 1.0 mm. This cell was operated for up to 1000 h under a constant load. The spiral cell exhibited a higher voltage and five times lower degradation rate than a serpentine cell which was analyzed for comparison. This effect was mainly attributed to the modified gas distribution, including the water vapor, which was verified by the computational fluid dynamics analysis.
Geometries of flow fields have a strong impact on the gas distribution in fuel cells. In this work, two different flow field geometries are compared for high temperature polymer electrolyte fuel cells, a serpentine like flow field and a spiral one. Computational fluid dynamics analysis yielded a mixed flow distribution over the active area of the spiral flow field. This cell exhibited a significantly higher voltage than the cell with the serpentine flow field. Additionally, the degradation rate of the cell with the spiral flow field was five times lower after an operation of 1000 h. Moreover, electrochemical impedance spectroscopy and cyclic voltammetry presented lower resistances and 50 % larger specific electrochemical surface area after long term tests for the cell with the spiral flow field compared to the one with the serpentine flow field.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.