TY - JOUR
T1 - Measurement of time-dependent changes and spatial distributions of current density in PEFC and water-content of PEM using a planer-surface coil as an NMR signal detector (second report: Effect of relative humidity and utilization ratio of fuel gas on current density distribution)
AU - Yokouchi, Yasuo
AU - Ogawa, Kuniyasu
AU - Haishi, Tomoyuki
AU - Ito, Kohei
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012
Y1 - 2012
N2 - To increase the electric power density of a polymer electrolyte fuel cell (PEFC), it is necessary to increase current density flowing through the membrane electrode assembly (MEA) in the whole PEFC. And this is controlled by the conditions of fuel gas such as flow rate and humidity. We measured the spatial distribution and time dependent changes of current density in the PEFC and the water content in PEM using Nuclear-Magnetic-Resonance (NMR) sensors in order to determine the effect of humidity and the utilization ratio of fuel gas. Our experimental results showed that the current density was uniformly distributed from the inlet to the outlet of the fuel gas when the flow rate was high and the humidity of the fuel gas was 70 %RH. On the other hand, when the flow rate was low and the humidity of the fuel gas higher (85 %RH), the spatial distribution of current density and water content in the PEM was non-uniform. We determined the relationship between the transfer phenomenon of water in the PEFC and this non-uniformity of water content and current density. In addition, a map illustrating the behavior of water content in the PEM and current density under electric-generating condition of the PEFC was made showing the relationship between relative humidity and utilization ratio of fuel gas supplied to the PEFC.
AB - To increase the electric power density of a polymer electrolyte fuel cell (PEFC), it is necessary to increase current density flowing through the membrane electrode assembly (MEA) in the whole PEFC. And this is controlled by the conditions of fuel gas such as flow rate and humidity. We measured the spatial distribution and time dependent changes of current density in the PEFC and the water content in PEM using Nuclear-Magnetic-Resonance (NMR) sensors in order to determine the effect of humidity and the utilization ratio of fuel gas. Our experimental results showed that the current density was uniformly distributed from the inlet to the outlet of the fuel gas when the flow rate was high and the humidity of the fuel gas was 70 %RH. On the other hand, when the flow rate was low and the humidity of the fuel gas higher (85 %RH), the spatial distribution of current density and water content in the PEM was non-uniform. We determined the relationship between the transfer phenomenon of water in the PEFC and this non-uniformity of water content and current density. In addition, a map illustrating the behavior of water content in the PEM and current density under electric-generating condition of the PEFC was made showing the relationship between relative humidity and utilization ratio of fuel gas supplied to the PEFC.
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U2 - 10.1299/kikaib.78.928
DO - 10.1299/kikaib.78.928
M3 - Article
AN - SCOPUS:84862116545
SN - 0387-5016
VL - 78
SP - 928
EP - 938
JO - Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
JF - Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
IS - 788
ER -