Fuel cells are a clean, energy-efficient alternative to combustion-based technologies used in power generation and storage applications. Converting hydrogen to electrical or thermal power via Polymer Electrolyte Membrane (PEM) fuel cells and using that energy to power vehicles and for distributed generation may replace most conventional internal combustion engines in the future. The United States Department of Energy is making significant investments to fund clean hydrogen technologies in the effort to achieve a net-zero carbon emissions by the year 2050.  Hydrogen is a clean fuel that, when consumed in a fuel cell, emits only water vapor and warm air. With zero carbon dioxide emissions, fuel cells offer a clean and safe option to address climate challenges now and into the future.

PEMs use hydrogen fuel and oxygen from the air to produce electricity. The Membrane Electrode Assembly (MEA) is an assembled stack of PEM, a catalytic layer, and a Gas Diffusion Layer (GDL). The MEA is between bipolar plates and gasket layers and these cells are stacked to produce a desired electrical output. The entire stack is commonly loaded with tie rods/studs to some optimal clamping pressure. Clamping force/pressure, or tightening torque, has an impact on the performance of PEM fuel cells. Optimal pressure is based on several factors:
  • Insufficient clamping force may result in leakage of the assembly.
  • Reduced clamping force results in increased contact resistance between the GDL and the bipolar plates and this reduces cell performance.
  • Excessive clamping force may reduce porosity of the GDL and reduce the flow of gas and liquid that can compromise cell performance.
  • Excessive clamping force may mechanically damage components of the cell.
In addition, the elastomer seals that are used in the fuel cell stack tend to relax or degrade over time and exposure to temperature, which can eventually reduce the cell performance.  Solon Belleville Springs can be assembled onto the tie rods to maintain optimal pressure on the fuel cell to not only prevent failures in the form of leaks or damage, but they can also improve the overall performance of the fuel cell. There are many spring designs and stacking arrangements that can be used for a fuel cell application. Our engineering team can help design the most cost-effective Belleville spring stack solution to meet your requirements.