Activation of electrochemical cells with catalyst electrodes
AssigneeH Power Corporation
InventorsZhigang Qi, Arthur Kaufman
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Abstract
A membrane-electrode assembly for electrochemical cells such as proton exchange membrane fuel cells and direct methanol fuel cells operating at ambient conditions are activated first by exposing them at a temperature higher than ambient temperature and with the gaseous reactants back-pressurized. The performance of the membrane-electrode assemblies, especially those whose electrodes are of low catalyst loadings made using supported catalysts, improves dramatically after the activation.
Claims12
A procedure for activating a membrane-electrode assembly (MEA) of an electrochemical cell operating at substantially ambient conditions, said activation procedure including the steps of:
- a) providing an electrochemical cell designed for operation at an ambient temperature and at substantially atmospheric pressure, said electrochemical cell comprising an MEA having a three-dimensional catalyst layer comprising a plurality of catalyst sites, a plurality of said catalyst sites being dead catalyst sites;
- b) prior to operating said electrochemical cell, activating said electrochemical cell by exposing the MEA to temperatures higher than ambient temperature, and substantially simultaneously back-pressurizing gaseous reactants at a pressure above atmospheric pressure so as to activate a portion of said dead catalyst sites;
- c) after the activation of the electrochemical cell, returning conditions of said electrochemical cell to ambient conditions;
- and
- d) operating said electrochemical cell at said ambient temperature and at substantially atmospheric pressure.
Dependencies are inferred from the claim text.