Abstract: Gas diffusion electrodes and gas-generating or consuming electrochemical cells utilizing the same are disclosed. The electrode comprises an electronically conductive and electrochemically active porous body defining respective gas and electrolyte contacting surfaces, with a substantially gas impermeable layer covering the electrolyte contacting surface. The layer comprises an electrolyte-insoluble, ionomeric ionically conductive hydrophilic hydrogel formed by coprecipitation between at least first and second precursor polymers.

Abstract: Gas diffusion electrodes and gas generating or consuming electrochemical cells utilizing the same are disclosed. The electrode comprises an electronically conductive and electrochemically active porous body defining respective gas and electrolyte contacting surfaces, with a substantially gas impermeable material filling at least a portion of the pore volume of the body so as to prevent gas passage therethrough. The material comprises an electrolyte-insoluble, ionomeric ionically conductive hydrophilic hydrogel formed by coprecipitation between at least two precursor polymers.

Abstract: Gas diffusion oxygen cathodes, oxygen consuming electrochemical cells utilizing such cathodes, and a method of preparing such cathodes are disclosed. The cathode comprises an electronically conductive porous body defining respective gas and electrolyte contacting surfaces. The cathode is prepared by forming the porous body, disposing the electrolyte contacting the gas contacting surface with a gaseous atmosphere. Current is passed through the porous body at a degree of electrode polarization much higher than normal whereby modification of the electrode material is effected. If desired, a transition metal macrocycle catalyst may be incorporated in the electrode and is subjected to pretreatment as well. The inventive electrodes exhibit superior voltage performance under oxygen reduction polarization conditions.

Abstract: Gas diffusion electrodes and gas generating or consuming electrochemical cells utilizing the same are disclosed. The electrode includes an electronically conductive and electrochemically active porous body defining respective gas and electrolyte contacting surfaces, with an ionomeric ionically conductive gas impermeable layer covering the electrolyte contacting surface. The layer includes a layer of a hydrophilic ionic polymer applied directly to the electrolyte contacting surface and a membrane of a hydrophilic ion exchange resin overlying the polymer layer.

Abstract: Gas diffusion electrodes, gas generating or consuming electrochemical cells utilizing such electrodes, and a method of preparing such electrodes are disclosed. The electrode comprises an electronically conductive porous body defining respective gas and electrolyte contacting surfaces. The electrode is prepared by forming the porous body, disposing the electrolyte contacting surface in contact with an electrolyte, and contacting the gas contacting surface with a gaseous atmosphere. Current is passed through the porous body at a degree of electrode polarization much higher than normal whereby modification of the electrode material is effected. If desired, a catalyst may be incorporated in the electrode and is subjected to pretreatment as well. The inventive electrodes exhibit superior voltage performance under oxygen polarization conditions.