Electrolyte additives for phosphoric acid fuel cells

Journal Article · Thu Apr 01 00:00:00 EST 1993 · Journal of the Electrochemical Society; (United States)

DOI:https://doi.org/10.1149/1.2056224· OSTI ID:6548381

Gang, X; Olsen, C; Berg, R W; Bjerrum, N J ^[1]; Hjuler, H A ^[2]

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1. Technical Univ. of Denmark, Lyngby (Denmark)
2. NKT Research Center, Brondby (Denmark)

Electrochemical characteristics of a series of modified phosphoric acid electrolytes containing fluorinated carbon compounds and silicone fluids as additives are presented. When used in phosphoric acid fuel cells, the modified electrolytes improve the performance due to the enhanced oxygen reduction rate. Among useful additives the authors found potassium perfluorohexanesulfonate (C[sub 6]F[sub 13]SO[sub 3]K), potassium nonafluorobutanesulfonate (C[sub 4]F[sub 9]SO[sub 3]K), perfluorotributylamine [(C[sub 4]F[sub 9])[sub 3]N], and polymethylsiloxanes [(-Si(CH[sub 3])[sub 2]O-)n]. The wettability of the electrodes by the modified electrolytes also is discussed, as if fuel-cell performance with the modified electrolytes. Specific conductivity measurements of some of the modified phosphoric acid electrolytes are reported. At a given temperature, the conductivity of the C[sub 4]F[sub 9]SO[sub 3]K-modified electrolyte decreases with an increasing amount of the additive; the conductivity of the (C[sub 4]F[sub 9])[sub 3]N-modified electrolyte, remains at the same value as the conductivity of the pure phosphoric acid. At a given composition, the conductivity of any modified electrolyte increases with temperature. The authors conclude that the improved cell performance for modified electrolytes is not due to any increase in conductivity.

• OSTI ID: 6548381
• Journal Information: Journal of the Electrochemical Society; (United States), Vol. 140:4; ISSN 0013-4651
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
ACID ELECTROLYTE FUEL CELLS
ELECTROLYTES
ADDITIVES
AMINES
CARBON FLUORIDES
ELECTRIC CONDUCTIVITY
PERFORMANCE
PHOSPHORIC ACID
POTASSIUM COMPOUNDS
SILICONES
SULFONATES
WETTABILITY
ALKALI METAL COMPOUNDS
CARBON COMPOUNDS
DIRECT ENERGY CONVERTERS
ELECTRICAL PROPERTIES
ELECTROCHEMICAL CELLS
FLUORIDES
FLUORINE COMPOUNDS
FUEL CELLS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHYSICAL PROPERTIES
POLYMERS
SILOXANES
300503* - Fuel Cells- Materials
Components
& Auxiliaries