In the world of maritime propulsion, there’s a growing buzz around polymer electrolyte membrane fuel cells (PEMFCs), particularly for air-independent applications. These systems, which operate with pure oxygen in closed environments, are being eyed for their potential to provide sustainable, long-endurance power. But before they can take the stage, there are some kinks to work out, as highlighted in a recent study published in the journal Case Studies in Thermal Engineering, which translates to English as “Case Studies in Thermal Engineering”.
At the heart of the matter are the membrane-electrode assemblies (MEAs) within these fuel cells. They’re subjected to some pretty harsh conditions, like high oxygen activity, prolonged high-voltage idling, and humidity or pressure transients. These are unique challenges for air-independent propulsion (AIP) systems, and they can lead to degradation over time. But until now, there hasn’t been a lot of research into how exactly these MEAs fail under these conditions.
Enter Jinhyuk Lim, a researcher from the Fuel Cell Stack Research Center at the Korea Automotive Technology Institute. Lim and his team set out to tackle this knowledge gap head-on. They designed five different test protocols to mimic the conditions MEAs might face in AIP systems. These included open-circuit voltage holding, load and relative-humidity cycling, and constant-current operation in both recirculation and dead-end modes.
What they found was that radical attack and mechanical fatigue were the primary culprits behind MEA degradation. “This study addresses the key question of which degradation pathways dominate under representative AIP operating profiles,” Lim explained. In other words, they’ve identified the main ways these MEAs can fail, which is a crucial step in making them more durable and reliable.
So, what does this mean for the maritime industry? Well, it’s a mixed bag. On one hand, these findings highlight the challenges that still need to be overcome before PEMFCs can be widely adopted for AIP systems. But on the other hand, they also provide a roadmap for how to tackle these issues. By understanding the main degradation pathways, researchers and engineers can develop strategies to mitigate them, whether that’s through better materials, improved designs, or more effective operating protocols.
For maritime professionals, this means that while PEMFCs for AIP systems might not be ready for prime time just yet, the future looks promising. As Lim puts it, “Durable performance under these AIP-specific stressors is critical for sustainable, long-endurance power systems.” And with continued research and development, we could be seeing more of these systems in our ships and submarines in the not-too-distant future.
In the meantime, it’s important for maritime stakeholders to stay informed about these developments. After all, the transition to sustainable, long-endurance power systems won’t happen overnight. But with researchers like Lim and his team paving the way, we’re making progress. And that’s something to be excited about.