Method for Preparing Membrane Electrode

At present, the industrialization process of PEMFC is still facing problems such as high cost and short life span. There are two main ways to improve the performance of PEMFC and reduce the cost of the system. One is to reduce the amount of precious metal Pt used from the perspective of the intrinsic activity of the catalyst by changing the carrier and preparing the alloy catalyst to improve the activity and stability of the catalyst. However, it is difficult to improve the performance of PEMFC in this way, because the electrochemical reaction process is also affected by many factors such as the three-phase interface and the mass transfer channels of electrons, protons, gas and water; the other is from the membrane electrode and the catalytic layer From the structural point of view, new membrane electrode preparation methods and preparation processes are explored to improve the performance of PEMFC. This method involves a wide range of factors, can coordinate the reaction process as a whole, and improve the performance of the fuel cell, which has become the focus of research.

The method recommended by our company to prepare membrane electrodes is ultrasonic coating. The membrane electrode prepared by the ultrasonic coating method has a high degree of automation, high efficiency, and low production of wood, which can meet the expansion of production. The utilization rate of platinum in the film using ultrasonic spraying is about 90%, reducing material consumption by up to 50% and reducing overspray, thereby saving expensive catalyst ink.

Ultrasonic spraying method is a MEA preparation method that has only been developed in recent years. The general process of this method is: first oscillate the catalyst slurry in an ultrasonic bath to disperse evenly, and then spray it on the support (GDL or GDL or PEM) on.

The ultrasonic spraying method has the following advantages:
(1) Adjust the ultrasonic frequency to make the ejected “ink” have a small rebound and not easy to spray, save the amount of catalyst, suitable for laboratory operations;
(2) In the state of high-frequency vibration, the catalyst is highly dispersed, agglomeration is reduced, the nozzle is not prone to clogging, and the arrangement of the catalyst sprayed on the support is also very uniform, so it can effectively prepare the film coating;
(3) Simple operation, automatic process, suitable for mass production of MEA. The disadvantage of the ultrasonic spraying method is that it consumes a lot of energy and becomes an obstacle to large-scale application.