Debate Over Bipolar Plates in PEM Fuel Cells: IDTechEx Examines the Metal vs Graphite Dispute in Detail
In the world of proton exchange membrane (PEM) fuel cells, a crucial component is the bipolar plate. These plates serve as structural support, a current collector, and a barrier between oxygen and hydrogen gases, playing a pivotal role in the efficient operation of fuel cells.
When it comes to choosing the appropriate material for bipolar plates, several factors come into play. Mechanical strength, corrosion resistance, electrical and thermal conductivity, and material costs are all key considerations. Traditionally, materials like titanium and steel have been popular choices due to their robust properties. However, as coating technologies improve, alternatives such as aluminum may become viable options.
For passenger cars and light commercial vehicles, metal bipolar plates are dominant due to the importance of form factor and energy density. In contrast, for heavy-duty applications like trucks, trains, and ships, graphite and graphite-based composite plates are better suited due to cost considerations.
Machining, stamping, and laser welding are methods used for creating channels in bipolar plates, with stamping being the predominant method for their formation. Challenges arise during post-fabrication processes, such as the removal of unwanted burrs and the need for a complex coating process.
One innovative approach to bipolar plate production is being developed by Bramble Engineering. They are utilising printed circuit board technology, with plans to license this unique technique to OEMs following proof of scalability.
Despite emerging alternatives, the choice between metal and graphite materials for bipolar plates remains a significant consideration in the PEM fuel cells industry. Companies like Ballard Power Systems and Hydrogenics are expected to use titanium or steel bipolar plates for PEM fuel cells from 2024 to 2034, and the development of new coating technologies that enable the use of other metals like aluminum is anticipated.
Early movers in the PEM fuel cell industry for heavy-duty applications are Toyota and Hyundai, using titanium and steel plates, respectively. The market value of bipolar plates in PEM fuel cells is predicted to surpass US$2.5 billion by 2034.
The IDTechEx report "Materials for PEM Fuel Cells 2024-2034: Technologies, Markets, Players" provides a comprehensive analysis of bipolar plates and other key components for PEM fuel cells, along with 10-year market forecasts. This report sheds light on the ongoing advancements and future trends in the field.
Coatings can be applied prior to stamping for graphite-based bipolar plates, but caution is necessary to avoid introducing defects that could lead to pinhole corrosion of the plate. Etching, including photochemical and laser methods, is a novel approach to producing bipolar plates, but it is not well-suited for graphite plates. Laser welding is utilised to seal any gaskets or other components to the bipolar plate.
As the PEM fuel cell industry continues to evolve, the choice between metal and graphite materials for bipolar plates will remain a significant consideration. Traditional manufacturing techniques are expected to continue to dominate the market in the mid-term and retain a significant market share in the long run, according to IDTechEx. However, innovative approaches like those being developed by Bramble Engineering could revolutionise the industry, offering new possibilities for the future of PEM fuel cells.
