GOALI: Pore-Scale Understanding of Ohmic Polarization in Solid Oxide Fuel Cell Electrodes

固体氧化物燃料电池（SOFC）是最有效的电转换装置之一，具有燃料灵活性，可适应来自废水处理厂、农场、垃圾填埋场的天然气和甲烷基沼气，以及清洁要求相对较低的生物质气化产品。然而，由于电池的电子电阻和离子电阻，SOFC中可能出现大量损耗。这些被称为欧姆极化的损失通常可以占SOFC电化学电势的40%以上，这取决于电池设计和操作条件。该研究将开发孔隙尺度模型，通过优化SOFC电极的微观结构来提高性能，从而了解和减少欧姆损失，从而使SOFC成为技术和经济上可行的替代能源，以实现高效的能量转换和可持续性。我们将1）使用PI和Xradia，Inc.开发的X射线计算机断层扫描（XCT）。以获得由Adaptive Materials，Inc. (AMI)作为分析的输入，2）开发50 nm分辨率的孔级模型以描述电极微结构中的电子和离子电荷转移，3）使用电荷转移预测结合热应力分析来确定XCT成像的SOFC电极结构的欧姆损失和结构完整性，和4）在Xradia和在AMI进行的SOFC实验中，用操作前和操作后SOFC电极的XCT成像验证预测。开发的模型将用于确定具有最小欧姆损耗的电极微观结构。这项工作将很好地结合我们目前的陆军资助的努力，碳氢化合物燃料的固体氧化物燃料电池，重点是在电极的孔结构的气相区域的质量传输，内部重整和电化学。这项活动将位于康涅狄格州全球燃料电池中心（CGFCC），该中心提供了全国最大的燃料电池科学和技术核心学术能力之一。该计划将涉及2名研究生，1名本科生，并将有外联活动，涉及7年级的高中生，教师和行业。

CBET-0828612ChiuThe solid oxide fuel cell (SOFC) is one of the most efficient electrical conversion devices with the fuel flexibility to accommodate both natural gas and methane-based biogases from wastewater plants, farms, landfills, and products from biomass gasification with relatively low cleaning requirements. However, substantial losses can arise in a SOFC due to the cell's electronic and ionic resistances. These losses, which are known as ohmic polarization, can generally account for upwards of 40% of the SOFC's electrochemical potential depending on the cell design and operating conditions. This research will develop pore-scale models to understand and reduce ohmic losses by optimizing the SOFC electrode microstructure for enhanced performance, thus enable the SOFC to be adopted as a technologically and economically viable alternative for efficient energy conversion and sustainability.A combination of x-ray imaging and model development will be used to achieve this goal. We will 1) use x-ray computed tomography (XCT) developed by the PI and Xradia, Inc. to obtain sub-50 nm resolution 3-D reconstruction of porous SOFC electrodes provided by Adaptive Materials, Inc. (AMI) as input for analysis, 2) develop pore-level models at 50 nm resolution to describe electronic and ionic charge transfer in the electrode microstructure, 3) determine ohmic losses and structural integrity of XCT-imaged SOFC electrode structures using charge transfer predictions coupled with thermal stress analysis, and 4) validate predictions with XCT imaging of pre- and post-operational SOFC electrodes at Xradia and SOFC experiments performed at AMI. Models developed will be used to determine electrode microstructures with minimal ohmic losses. This work will integrate well with our current Army-funded effort on hydrocarbon-fueled SOFC that focuses on mass transport, internal reformation and electrochemistry in the gas phase region of the electrode's pore structure. This activity will be located at the Connecticut Global Fuel Cell Center (CGFCC), which offers one of the largest core academic capabilities in fuel cell science and technology in the nation. The program will involve 2 graduate students, 1 undergraduate student, and will have outreach activities involving 7th grade to high school students, teachers and industry.