High-uniformity CCM continuous coating process for fuel cell

Abstract

The invention discloses a fuel cell CCM preparation process, which comprises the following steps: respectively preparing anode low-concentration catalyst slurry and cathode high-concentration catalyst slurry, coating the low-concentration catalyst slurry on the A surface of a proton exchange membrane, drying to prepare the anode side of the CCM, coating the high-concentration catalyst slurry on the B surface of the proton exchange membrane, and drying to prepare the cathode side of the CCM. And drying to serve as a cathode side, and finally preparing the CCM with the distinguishable cathode and anode. Wherein the drying mode for the low-concentration catalyst slurry is that the low-concentration catalyst slurry firstly enters a drying tunnel to be in a gel state and then is subjected to hot pressing; the drying mode for the high-concentration catalyst slurry is tunnel drying; the CCM cathode and the CCM anode can be distinguished, and meanwhile, the uniformity of the CCM coating is relatively improved, so that the percent of pass is increased, and the waste phenomenon is reduced.

Description

technical field [0001] The invention relates to the field of fuel cells, in particular to a high-uniformity CCM continuous coating process for fuel cells. Background technique [0002] Fuel cell CCM is one of the important components of fuel cells. The main process is to coat the catalyst slurry on the proton exchange membrane and form CCM after drying. In the existing CCM preparation process, its surface uniformity has always been a key research and development technology in this field. One, at the same time, for the cathode and anode of CCM, in this field, the cathode and anode are mostly distinguished by the level of loading, that is, the one with high loading is the cathode side, and the one with low loading is the anode side. However, in the preparation process of CCM, the loading It is difficult to control the amount of high and low. Since the slurry loading on both sides of the CCM is required to be different, the slurry needs to be strictly regulated in terms of the ...

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Problems solved by technology

[0003] On the other hand, in the CCM preparation process, the catalyst slurry itself has a certain fluidity. After it is coated on the proton exchange membrane, there will be a microscopic flow phenomenon during the continuous transmission of the membrane. At this time, the It will affect the uniformity of the coating surface; in order to reduce the flow of the slurry, the concentration of the slurry can be increased when preparing the catalyst slurry, but the slurry with a higher concentration, due to its poor fluidity and high surface tension , so there are still many particles after the slurry is stirred, and combined with the problem of weak adhesion of the slurry on the surface of the proton membrane, it leads to uniformity problems such as particles, pinholes, and defects on the final CCM surface, which directly affects the CCM pass rate

[0004] In order to solve the above problems in the prior art, most of them use CCM for preparing thin-layer coatings or adopt multiple coating processes combined with CCD detection equipment to improve the pass rate of CCM, but thin-layer coatings do not meet the actual performance requirements, and multiple coatings Although the method of coating can improve the uniformity problem, problems such as film swelling and catalytic layer cracks during each coating are also technical problems in the existing field, and the subsequent use of CCD detection can only improve the pass rate of the final product, but cannot reduce The failure rate will eventually lead to a certain degree of waste

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