This study utilized a transparent direct methanol fuel cell, with serpentine channels with a width of 2 mm and an initial depth of 2 mm, and investigated the relationship between the behaviours of carbon dioxide (CO2) slugs, product water accumulations, and voltage fluctuation. It examined the exhaust volumes of CO2 slugs and product water accumulations from the channels over time, comparing an anode channel with a depth of 1.2 mm to one with a depth of 2 mm (without changing the cathode depth of 2 mm, nor the width of 2 mm in both the anode and the cathode). Results indicated that cell voltage fluctuated, rising while CO2 slugs were ejected, and falling between ejections. In the case of an anode channel depth of 2 mm and a lower methanol-water solution flow rate, CO2 slugs were ejected less frequently, so cell voltage fluctuated widely. (Product water accumulations in the cathode had a minimum effect on this cell voltage fluctuation.) In the case of a higher methanol-water solution flow rate, CO2 slugs were ejected more frequently, with less exhaust volume per CO2 slug, reducing the fluctuation in cell voltage. Finally, with an anode channel depth of 1.2 mm, the exhaust volume per CO2 slug became even smaller, and these small CO2 slugs were rapidly ejected. With this shallow depth, the cell voltage increased with a lower methanol-water solution flow rate, but decreased with a higher methanol-water solution flow rate by crossover.
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 Argyropoulos, P., Scott, K., Taama, W. M., Carbon dioxide evolution patterns in direct methanol fuel cells, Electrochimica Acta, Vol. 44, pp. 3575-3584, 1999.
 Burgmann, S., Blank, M., Wartmann, J., Heinzel, A., Investigation of the effect of CO2 bubbles and slugs on the performance of a DMFC by means of leaser-optical flow measurements, Energy Procedia, Vol. 28, pp. 88-101, 2012.
 Calabriso, A., Borello, D., Romano, G. P., Cedola, L., Zotto, L. D., Santori, S. G., Bubbly flow mapping in the anode channel of a direct methanol fuel cell via PIV investigation, Applied Energy, Vol. 185, Part 2, pp. 1245-1255, 2017.
 Hsieh, S., Wu, H., Her, B., A novel design for a flow field configuration, of a direct methanol fuel cell, Journal of Power Sources, Vol. 195, pp. 3224-3230, 2010.
 Liao, Q., Zhu, X., Zheng, X., Ding, Y., Visualization study on the dynamics of CO2 bubbles in anode channels and performance of a DMFC, Journal of Power Sources, Vol. 171, pp. 644-651, 2007.
 Lu, G. Q., Wong, C. Y., Electrochemical and flow characterization of a direct methanol fuel cell, Journal of Power Sources, Vol. 134, pp. 33-40, 2004.
 Murakami, K., Nakashima, K., Murakami, Y., Experimental Development of a Small Transparent Direct Methanol Fuel Cell, Journal of Japan Society for Design Engineering, Vol. 46, No. 8, pp. 439-442, 2011 (in Japanese).
 Nakashima, K., Shimizu, H., Inagaki, R., Effect of Flow Channel Size on Carbon Dioxide and Product Water Exhausts in a Small Direct Methanol Fuel Cell, Proceedings of the 6th European Fuel Cell Piero Lunghi Conference, pp. 157-158, 2015.
 Nakashima, K., Carbon Dioxide and Product Water Exhausts in a Small Direct Methanol Fuel Cell with Different Sizes of Serpentine Channels, Proceedings of the 7th European Fuel Cell Piero Lunghi Conference, pp. 343-344, 2017.
 Scott, K., Taama, W. M., Argyropoulos, P., Engineering aspects of the Direct methanol fuel cell system, Journal of Power Sources, Vol. 79, pp. 43-59, 1999.
 Yang, H., Zhao, T. S., Effect of anode flow field design on the performance of liquid feed direct methanol fuel cells, Electrochimica Acta, Vol. 50, pp. 3243-3252, 2005.
 Yang, H., Zhao, T. S., Ye, Q., In situ visualization study of CO2 gas bubble behaviour in DMFC anode flow fields, Journal of Power Sources, Vol. 139, pp. 79-90, 2005.