Audi Ag

United Technologies Corporation

Laura Roen Stolar

Jesse M Marzullo

Robert Mason Darling

Sergei F Burlatsky

Lesia V Protsailo

Mallika Gummalla

Elise Lorraine Izzo

Krista Marie Shoemaker

Shriram Ramanathan

A flow battery includes a liquid electrolyte having an electrochemically active specie. A flow field plate includes a first flow field channel and a second flow field channel that is separated from the first flow field channel by a rib. There is a flow path for the liquid electrolyte to flow over the rib between the channels. An electrode is arranged adjacent the flow field plate such that the liquid electrolyte that flows over the rib must flow through the electrode. The electrode includes a carbon paper that is catalytically active with regard to liquid electrolyte. The carbon paper defines a compressive strain of less than 20% at a compressive stress of 0.8 MPa and an uncompressed porosity in the range 60-85%.

Flow battery with carbon paper

A catalyst layer for use in a fuel cell includes catalytic nanoparticles and a perfluorosulfonic acid (PFSA) ionomer. The catalytic nanoparticles have a palladium or palladium alloy core and an atomically thin layer of platinum on an outer surface of the palladium or palladium alloy core. The PFSA ionomer has an equivalent weight equal to or greater than about 830. A unitized electrode assembly is also described.

Unitized electrode assembly with high equivalent weight ionomer

A unitized electrode assembly () for a fuel cell includes, in addition to an anode catalyst layer () and a cathode catalyst layer (), a polymer electrolyte membrane () having an acid functional group normally including Hions and an edge seal () containing alkali metal ions in a form, concentration, and/or location for delivery and dispersion into the membrane. The edge seal of the unitized electrode assembly is proximate, and typically contacts, the peripheral edge region () of the membrane in ion-transfer relation therewith, and alkali metal ions leach into the membrane during fuel cell operation to provide a desired ion exchange in the membrane. The alkali metal ions contained by the edge seal may be Li, Na, K, Rb, and/or Cs, and may be included as a dopant with the material of the edge seal during its formation, or may be included as a discrete component of the edge seal, as by an ion-doped strip of membrane material contained by the edge seal. The edge seal thus serves as a 'reservoir' of the alkali metal ions for release to the polymer electrolyte membrane for increased durability.

Protective edge seal having alkali metal ions for membrane ion exchange

An example of a stable electrode structure is to use a gradient electrode that employs large platinum particle catalyst in the close proximity to the membrane supported on conventional carbon and small platinum particles in the section of the electrode closer to a GDL supported on a stabilized carbon. Some electrode parameters that contribute to electrode performance stability and reduced change in ECA are platinum-to-carbon ratio, size of platinum particles in various parts of the electrode, use of other stable catalysts instead of large particle size platinum (alloy, etc), depth of each gradient sublayer. Another example of a stable electrode structure is to use a mixture of platinum particle sizes on a carbon support, such as using platinum particles that may be 6 nanometers and 3 nanometers. A conductive support is typically one or more of the carbon blacks.

Fuel cell electrode with gradient catalyst structure

A method of forming a catalyst material includes coating agglomerates of catalyst support particles with an ionomer material. After coating the agglomerates of catalyst support particles, a catalyst metal precursor is deposited by chemical infiltration onto peripheral surfaces of the agglomerates of catalyst support particles. The catalyst metal precursor is then chemically reduced to form catalyst metal on the peripheral surfaces of the agglomerates of catalyst support particles.

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South Windsor, CT, United States of America

Laura Roen Stolar