Abstract: A gas diffusion composite electrode is disclosed which is suitable for use in combination with an electrically conductive current collector. The electrode comprises an electrochemically active, porous and heterogeneous layer containing (1) an interconnected, hydrophilic island material comprising a blend of a major amount of an electrically conductive, particulate material, such as carbon black, in combination with an electrochemically active catalyst, and a minor amount of a hydrophobic polymer in combination with (2) a hydrophobic matrix material consisting essentially of a hydrophobic polymer rendered substantially porous by removal of a pore-forming ingredient. Methods of preparing the heterogeneous layer and the composite electrode are also disclosed.

Abstract: The invention is an electrode comprising:(a) an electrically conductive first layer having a plurality of interconnecting passageways of an average diameter of from about 0.1 to about 1.0 microns,said first layer containing from about 2 to about 10 weight percent of a catalyst active for the reduction of oxygen, and having a hydrophobic carbon containing from about 85 to about 95 weight percent carbon and from about 5 to about 15 weight percent of a first hydrophobic material,(b) an electrically conductive second layer in fluid flow communication with the first layer and having a plurality of interconnecting passageways of an average diameter of from about 0.

Abstract: A gas diffusion composite electrode is disclosed which is suitable for use in combination with an electrically conductive current collector. The electrode comprises an electrochemically active, porous and heterogeneous layer containing (1) an interconnected, hydrophilic island material comprising a blend of a major amount of an electrically conductive, particulate material, such as carbon black, in combination with an electrochemically active catalyst, and a minor amount of a hydrophobic polymer in combination with (2) a hydrophobic matrix material consisting essentially of a hydrophobic polymer rendered substantially porous by removal of a pore-forming ingredient. Methods of preparing the heterogeneous layer and the composite electrode are also disclosed.

Abstract: A gas diffusion composite electrode useful in an electrochemical cell comprising an electrochemically active layer and a backing layer, said active layer characterized as porous, homogeneous, hydrophilic, and electrolyte-permeable and comprising a sintered mixture of a major amount of an electrically conductive, hydrophilic, particulate material containing admixed therewith an electrochemically active catalyst, and a minor amount of a hydrophobic polymer, said particulate material being substantially coated with said hydrophobic polymer by precipitation of said hydrophobic polymer upon said particulate material.