Wetting-in studies on alkaline-fuel-cell cathodes using a potentiostatic-galvanostatic experimental design

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Journal of the Electrochemical Society; (United States)

DOI:https://doi.org/10.1149/1.2054953· OSTI ID:7258639

Lundblad, A; Bjoernbom, P ^[1]

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1. Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

The influence of potential and current on electrolyte intrusion during the initiation phase of poly(tetrafluoroethylene)-(PTFE)-bonded carbon cathodes has been studied. A potentiostatic-galvanostatic experimental design was used. This was attained by varying the oxygen concentration using a computerized control circuit. The intrusion depth was determined by an electron microscope element-mapping method, and the amount of intruded electrolyte was determined by weighing. The wetting-in of the electrode was found to depend strongly on potential and less on applied current density. A combination of electrocapillarity and electro-osmosis is proposed as an explanation of the results. The experiments have also revealed interesting phenomena concerning electrolyte and three-dimensional current-density distribution during the initiation phase. From the results, a mechanism for the sudden failure (flooding) of PTFE-bonded carbon cathodes at the end of their service life is suggested.

• OSTI ID: 7258639
• Journal Information: Journal of the Electrochemical Society; (United States), Journal Name: Journal of the Electrochemical Society; (United States) Vol. 141:6; ISSN JESOAN; ISSN 0013-4651
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
300503* -- Fuel Cells-- Materials
Components
& Auxiliaries
ALKALINE ELECTROLYTE FUEL CELLS
CATHODES
CURRENT DENSITY
DIRECT ENERGY CONVERTERS
ELECTRIC POTENTIAL
ELECTROCHEMICAL CELLS
ELECTRODES
FAILURES
FLUORINATED ALIPHATIC HYDROCARBONS
FUEL CELLS
HALOGENATED ALIPHATIC HYDROCARBONS
LIFETIME
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC POLYMERS
POLYETHYLENES
POLYMERS
POLYOLEFINS
POLYTETRAFLUOROETHYLENE
SERVICE LIFE
START-UP
WETTABILITY