Fuel cell catalyst layer and membrane electrode subassembly and preparation method thereof

Abstract

A fuel cell membrane electrode subassembly comprises an electrolyte membrane and catalyst layers attached to two sides of the electrolyte membrane. The catalyst layer is a porous thin-layer with a conductive high-molecular polymer-electrocatalyst as the framework. Thickness of the thin-layer is 10-500 microns; pore diameter of the thin-layer is 1-50 microns; and pore wall thickness is 0.1-1 micron. When the electrolyte membrane is a proton exchange membrane, the conductive high-molecular polymer is a cationic conductive high-molecular polymer. When the electrolyte membrane is an alkaline anion-exchange membrane, the conductive high-molecular polymer is an anionic conductive high-molecular polymer. A preparation method of the catalyst layer comprises the following steps: dispersing catalyst slurry on a substrate surface, refrigerating below 0 DEG C for no less than 5 h, and carrying out vacuum drying so as to obtain a catalyst layer attached to the substrate surface. The catalyst slurry comprises an electrocatalyst, a conductive high-molecular polymer and solvent water. In comparison with the prior art, the product of the invention has low loss late of catalyst and good repeatability, is not influenced by environmental factor and is easy for batch preparation. The catalyst in the catalyst layer or the membrane electrode subassembly prepared by the method has advantages of uniform distribution, high utilization rate, controllable pore structure and the like.

Description

technical field [0001] The present invention relates to a kind of fuel cell catalytic layer, specifically a kind of catalytic layer for proton exchange membrane fuel cell, direct liquid fuel cell and proton exchange membrane type water electrolysis cell; The present invention also relates to the preparation method of above-mentioned catalytic layer . [0002] The present invention also relates to the membrane electrode assembly prepared by the method for preparing the catalytic layer. Background technique [0003] In order to improve the performance of the catalytic layer, reduce the amount of electrocatalyst and improve the catalytic efficiency, designing a gas diffusion electrode with high mass transfer efficiency is the key to success. At the same time, for the mass production of gas diffusion electrodes, the performance, stability and consistency of gas diffusion electrodes are the core indicators of the product. At present, the commonly used method for preparing gas d...

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Problems solved by technology

However, the catalyst preparation methods commonly used at present, such as brushing and spraying, have a large loss rate of the catalyst, and because the preparation process passes through the solvent volatilization process, even the solvent volatilization under natural conditions, the resulting film swelling and catalytic layer cracking , uneven thickness and other problems cannot be solved, the pore structure and distribution of the prepared membrane electrode performance are greatly affected by environmental factors, so the repeatability and consistency of the obtained products are not good

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