NPL has world-leading capabilities in fuel cell measurements, as well as corrosion testing. Combining these areas of expertise, NPL carried out a range of analyses of Bramble's materials to help them understand their degradation mechanisms, and recommend areas for improvement.
During the nine-month project, Bramble was able to access NPL's state-of-the-art imaging and electrochemical testing facilities, including electron microscopy and electrochemical analysis, as well as its expertise in fuel cell degradation mechanisms.
The most important finding was the unexpected presence of silicon rods scattered around the surface, causing localised stresses. Bramble worked with their manufacturer to identify the source of these rods – an innocuous skimming process – and developed a new manufacturing approach which will eliminate the problem.
Rigorous analyses of samples by NPL before and after degradation testing, and subsequent recommendations, provided Bramble with insight into degradation mechanisms, and helped them tailor their materials selection to improve durability. Testing to date on the new passivation layer suggests these changes have slowed the degradation and will significantly improve durability.