US 4,058,482 AGranted

Fuel cell electrode

AssigneeUnited Technologies Corporation

InventorsJohannes M. Baris, Charles D. Iacovangelo, Wolfgang M. Vogel

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Abstract

A sheet material, principally comprised of a polymer such as polytetrafluoroethylene, having characteristics which permit its use in a fuel cell electrode is formed from co-agglomerates of the polymer and a pore former. In a fuel cell electrode application, the polymer-pore former agglomerates are themselves caused to co-agglomerate with a catalyst, the resulting co-agglomerates are formed into a layer and the pore former is leached from the layer so as to produce a structure having gas channels only in the polymer portions thereof. Agglomeration of the pore former and polymer particles is permitted through first imparting a positive charge to the pore former particles. The gas permeable catalyst layer will be bonded to a support plate to define a fuel cell electrode.

Claims3

Dependent claims

A method for the manufacture of a fuel cell electrode comprising the steps of:

choosing a polymer, the polymer being selected to be in the form of negatively charged particles having a desired average diameter;
selecting a pore former, the pore former comprising a material which is attacked by an etchant which will not attack the polymer, the pore former being in the form of positively charged particles having an average diameter which is not greater than the average diameter of the polymer particles;
causing the polymer and pore former particles to co-agglomerate;
forming a suspension containing the polymer-pore former co-agglomerates and particles of a fuel cell catalyst;
intimately mixing the co-agglomerates and particles of catalyst;
filtering the suspension to form a layer comprising polymer-pore former co-agglomerates and catalyst;
mounting the layer on a support to define a fuel cell electrode structure;
sintering the electrode structure;
and
subjecting the sintered electrode structure to an etchant which will attack the pore former material to thereby produce an electrode having gas channels only in the polymer portions thereof.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/752,417Filed 20 Dec 1976
Granted: 15 Nov 1977
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H01M 4/8663
Inert electrodes with catalytic activity, e.g. for fuel cells: selection of inactive substances as ingredients for catalytic active masses, e.g.…
H01M 4/8668
Selection of inactive substances as ingredients for catalytic active masses, e.g. binders, fillers: binders
H01M 4/8807
Supports for the deposition of the catalytic active composition: gas diffusion layers
H01M 4/8875
Processes of manufacture: methods for shaping the electrode into free-standing bodies, like sheets, films or grids, e.g. moulding, hot-pressing,…