Fuel Cell Coating Knowledge

Fuel Cell Functional Coating

Fuel Cell Coating, also known as Fuel Cell Functional Coating, is a core and critical process for hydrogen fuel cells and electrolyzed water membrane electrode assemblies. It is widely used in the two mainstream scenarios of Proton Exchange Membrane Fuel Cells (PEMFC) and Solid Oxide Fuel Cells (SOFC). The core coatings in the industry are mainly divided into four categories: the first is the core catalytic layer, which includes two mainstream processes: CCM membrane coating catalysis and CCS based coating catalysis. It is coated with platinum carbon catalyst, ionomer and other proportioned slurries, directly determining the power generation performance of the fuel cell stack; The second is the protective coating for metal bipolar plates, mainly composed of carbon based, titanium nitride, and composite coatings, which balance low contact resistance and acid and alkali corrosion resistance; The third is the gas diffusion layer coating, which optimizes gas mass transfer and avoids water flooding of the fuel cell stack through PTFE hydrophobic layer and carbon black microporous layer; The fourth is a high-temperature coating specifically designed for SOFC, covering high-temperature resistant functional layers such as YSZ electrolyte and LSM cathode, suitable for high-temperature working conditions.

Fuel cell coatings have multiple mature preparation processes that are suitable for different needs of research and development trials and industrial mass production. Among them, ultrasonic spraying is currently the mainstream high-quality process. With the advantages of low-pressure soft atomization, material utilization rate of over 90%, and uniform coating without agglomeration, it significantly reduces the loss of precious metal platinum materials, while not damaging proton membranes and carbon paper substrates. It can achieve gradient coating customization, optimize the three-phase interface of electrochemical reactions, and adapt to various MEA catalytic layer processing. In addition, slit coating is suitable for large-scale production of high-speed roll to roll, with strong process stability; The heat transfer printing process can avoid swelling and deformation of proton membranes, and is commonly used for high-end low platinum membrane electrodes; Screen printing, magnetron sputtering and other processes are respectively suitable for the preparation needs of high-temperature solid oxide batteries and ultra-low platinum ultra-thin coatings.

The performance of fuel cell coatings directly determines the efficiency, lifespan, and cost of the fuel cell stack, and the industry has a unified core assessment index. The key parameters include catalyst loading, coating thickness, in-plane uniformity, porosity, coating adhesion, and ionomer carbon ratio. These parameters balance each other to ensure stable operation of proton conduction, gas circulation, and drainage and heat dissipation. High quality functional coatings can effectively improve catalyst utilization, reduce stack internal resistance, and delay substrate corrosion and aging. They are the core technical support for achieving low platinum, high stability, and long-life mass production applications of fuel cells, and are also a key link in the industrial upgrading of hydrogen fuel cells.