TY - GEN
T1 - Estimation of water layer thickness adjacent to the cathode catalyst layer of a PEFC (analysis using electrochemical impedance spectroscopy)
AU - Hoshiko, T.
AU - Nakajima, H.
AU - Konomi, T.
AU - Kitahara, T.
AU - Kita, S.
PY - 2008/12/1
Y1 - 2008/12/1
N2 - We have analyzed the impedance of the cathode of a polymer electrolyte fuel cell (PEFC) to estimate oxygen diffusion distance, δ. Assuming planar oxygen diffusion in a thin liquid water layer at the cathode unconventionally, we can regard δ as water layer thickness adjacent to the cathode catalyst layer. Calculated values of δ agree well with our previous experimental result of liquid water accumulation amount at the cathode. Measurement of impedance variation with time reveals that δ initially tends to be almost constant with time after start-up from dry condition, but that excessive water accumulation due to long time operation causes an increase in δ. From the viewpoint of the diagnosis, an exceeding increase in δ can be used to indicate the flooding at the catalyst layer.
AB - We have analyzed the impedance of the cathode of a polymer electrolyte fuel cell (PEFC) to estimate oxygen diffusion distance, δ. Assuming planar oxygen diffusion in a thin liquid water layer at the cathode unconventionally, we can regard δ as water layer thickness adjacent to the cathode catalyst layer. Calculated values of δ agree well with our previous experimental result of liquid water accumulation amount at the cathode. Measurement of impedance variation with time reveals that δ initially tends to be almost constant with time after start-up from dry condition, but that excessive water accumulation due to long time operation causes an increase in δ. From the viewpoint of the diagnosis, an exceeding increase in δ can be used to indicate the flooding at the catalyst layer.
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U2 - 10.1149/1.2982051
DO - 10.1149/1.2982051
M3 - Conference contribution
AN - SCOPUS:63149171100
SN - 9781566776486
T3 - ECS Transactions
SP - 2117
EP - 2123
BT - ECS Transactions - Proton Exchange Membrane Fuel Cells 8
T2 - Proton Exchange Membrane Fuel Cells 8, PEMFC - 214th ECS Meeting
Y2 - 12 October 2008 through 17 October 2008
ER -