Improving porous transport layers for PEM fuel cells and electrolyzers

对风能和太阳能等可再生能源产生的清洁电力的需求巨大。然而，由于与可再生能源相关的固有不稳定性，清洁电力必须立即使用或储存以备后用。由可再生电力供电的聚合物电解质膜（PEM）电解槽可用于产生氢气，随后用作PEM燃料电池的燃料。当与可再生能源配对时，PEM燃料电池提供零排放的电力。然而，PEM燃料电池和氢气的成本目前限制了广泛的商业应用。热量和质量传输问题导致的低效操作导致了这些高成本。随着效率和性能的提高，可以生产更小的燃料电池，以满足商业应用的电力需求。这里提出的研究包括一个由三部分组成的计划，旨在克服PEM燃料电池和电解槽的挑战。首先，我们将使用计算机断层扫描来表征多孔传输层，以便更好地理解材料结构。其次，我们将使用X射线照相术可视化液体和气体的多相输送，以了解流体在操作过程中的行为。最后，我们将使用第一部分和第二部分的组合信息来构建热量和质量传输模型，这些模型可用于设计新材料，以通过制造提供更多功率的更小设备来提高性能和降低成本。PEM燃料电池和电解槽具有为绿色能源格局提供基础的巨大潜力，在汽车，备用电源，离网社区中具有实际应用，并且最及时地促进从风能和太阳能中产生具有成本效益的清洁能源。

The need for clean electricity generated from renewable energy sources, such as wind and solar, is tremendous. However, due to the inherent intermittency associated with renewable energy sources, clean electricity must be used immediately or stored for later use. The polymer electrolyte membrane (PEM) electrolyzer powered by renewable electricity can be used to generate hydrogen for later use as fuel for PEM fuel cells. When paired with renewable energy sources, PEM fuel cells provide electricity with zero emissions. However, the cost of PEM fuel cells and hydrogen currently limit widespread commercial adoption. Inefficient operation from heat and mass transport issues contributes to these high costs. With improved efficiencies and performance, smaller fuel cells can be produced to meet the power demands of commercial applications. The research proposed here includes a three-part plan designed to overcome the challenges of PEM fuel cells and electrolyzers. First we will characterize the porous transport layers using computed tomography in order to better understand the material structures. Second, we will visualize the multiphase transport of liquid and gas using X-ray radiography to see how the fluids behave during operation. Finally we will use the combined information from the first and second parts to build heat and mass transport models that can be used to design new materials for both improved performance and cost reduction through the manufacture of smaller devices that deliver more power. PEM fuel cells and electrolyzers have enormous potential for providing a foundation for a green energy landscape, with practical applications in automotives, backup power, off-grid communities, and most timely, in facilitating the generation of cost-efficient clean energy from wind and sun.