There has been controversy or discussion in the hydrogen fuel cell industry, that is, whether the future of hydrogen fuel cell is metal plate or china graphite plate components. Based on this topic, we have made some simple analysis according to the performance requirements and cost of china graphite plate components.

1. From the perspective of electrochemical demand function

1) Reaction gas and coolant channels are formed.
From this point of view, there is no essential difference between china graphite plate components and metal plate. As far as the current channel section requirements are concerned, the functions can be basically realized, and the processed china graphite plate components will be slightly insufficient in the processing of special-shaped channels; There is almost no difference in the type of runner between molded graphite plate and stamped metal plate.
2) Conductivity / thermal conductivity
From the overall direction of material properties, the conductivity of china graphite plate components is almost four times that of stainless steel, and the thermal conductivity is much better than that of stainless steel. Of course, in terms of demand, both metal plate and china graphite plate components can meet the demand of fuel cells.
3) Drainage system. Prevent channel blockage, water injection and other faults
The current situation is to carry out some hydrophobic treatment on the surface of bipolar plate, such as soaking in hydrophobic solution or other surface treatment. There is not much difference at this level.
4) Corrosion resistance. It is mainly used to prolong the service life
In order to improve the corrosion resistance of stainless steel metal plate, a variety of process coating treatment methods are adopted, but at least the current situation is unmatched by china graphite plate components. At this point, the china graphite plate components won completely.
2. From the perspective of mechanical performance requirements
1) Mechanical strength. Because the bipolar plate plays a supporting role in the whole stack. Relatively speaking, metal plate is superior to graphite plate in this regard. Especially under the locking force after laminated assembly, the china graphite plate components may have extrusion defects, which is very important.
2) Power density problem.
In terms of density, the density of stainless steel is about 4 times that of graphite, so from the perspective of weight reduction, we must consider the volume of the final bipolar plate and the thickness in the same area. Because the current metal plate is thinner, it can reach 1.1 ~ 1.3mm; The relatively thin graphite plate components is also about 1.3 ~ 1.6mm. Therefore, from this point of view, the volume power density of metal plate is more dominant.
3. Service life comparison
At present, the data provided by most metal plate suppliers are between 5000 and 10000 hours; The china graphite plate components can provide 12000 to 30000 working hours. At present, china graphite plate components has obvious advantages in this regard.
Service life is a data that needs to be verified by long-term actual engineering operation. Although there are some alternative durability verification schemes and standards, they can only be used as a reference.
4. Cost problem
The factors affecting the cost come from two levels. First, the material itself; Second, processing technology. In terms of raw materials, the unit price of stainless steel is close to twice that of graphite. However, in terms of the complexity of the processing process, the processing process of metal plate should be easier than that of china graphite plate components.