Gas diffusion cathodes, electrochemical cells and methods exhibiting improved oxygen reduction performance

摘要

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.