Continuous coating process for fuel cell membrane electrode (CCM)

Abstract

The invention discloses a continuous coating process for a fuel cell membrane electrode (CCM). The continuous coating process comprises the following steps: mixing a high-molecular polymer, an alcohol organic solvent, a pore-foaming agent and solid catalyst particles, and uniformly stirring and dispersing at a high speed under the assistance of ultrasonic waves; coating the proton exchange membrane with the catalyst slurry by using roll-to-roll continuous coating equipment to form a catalyst layer I; transferring the formed catalyst layer I into a dipping tank I, removing the pore-foaming agent, and then carrying out secondary continuous coating to obtain a catalyst layer II; transferring the formed catalyst layer II into a dipping tank II, removing the pore-foaming agent again, and drying to form a porous catalyst layer; according to the invention, the pore-forming agent is selectively added, and coating and dipping removal are carried out for multiple times, so that the porosity of the catalyst layer is greatly increased, the transmission resistance of gas in the catalyst layer is reduced, the membrane electrode with high mass transfer capability is constructed, the performance of the battery is improved, and the service life of the battery is prolonged.

Description

technical field [0001] The invention relates to a continuous coating process for a catalytic layer of a fuel cell membrane electrode, which belongs to the field of fuel cell membrane electrodes. Background technique [0002] For proton exchange membrane fuel cells using hydrogen as fuel, its electrochemical catalytic activity is mainly restricted by the electrode, because the catalytic activity of the Pt catalyst, especially for the reduction reaction of cathode oxygen, is low. The cathode and anode catalytic layers generally use carbon-supported nano-Pt, Pd noble metals or their alloys as catalysts. During the electrochemical process at the cathode of the fuel cell, the oxygen in the air diffuses to the proton exchange membrane through the gas diffusion layer (GDL), and the hydrogen protons generated by the electrochemical reaction at the anode are transferred to the cathode through the proton exchange membrane. After the protons and oxygen meet at the active sites on the ...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the dispersion effect of the slurry is poor, the prepared catalyst slurry is unevenly mixed and dispersed, and it is easy to delaminate and settle.

At the same time, the distribution of polymer proton conductors in the catalytic layer prepared by the existing method is not uniform, which is not conducive to the transmission of reaction gases, resulting in the loss of catalyst utilization and the reduction of battery life.

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