Material Characterization using Micro Computed Tomography and Pore Network Modeling of Gas Diffusion Layers for Fuel cell Applications

汽车燃料电池合作公司（AFCC）正在为其2013年生产线开发下一代燃料电池堆。尽管聚合物电解质膜燃料电池（PEMFC）是用于汽车应用的有前途的能量转换装置，但该技术仍然面临与液态水管理相关的几个障碍。为了提供实用的水管理解决方案，对燃料电池的多孔层内的气态和液态水的传输机制的强有力的基本理解对于设计将在高电流密度操作下使用的PEMFC是至关重要的，其中存在大量的液态水。在这里提出的工作中，AFCC正在支持一项双管齐下的努力：1）使用微型计算机断层扫描（µCT）开发材料表征策略，以深入了解燃料电池中使用的多孔材料的微观结构; 2）开发一种孔隙网络建模工具，最终使AFCC能够预测这些多孔材料的液态水通量和饱和状态，作为气体燃料的函数电化学反应位点的扩散率。在接下来的两年里，AFCC将与调查人员合作，为学员提供对下一代燃料电池堆所面临的行业特定问题的透明理解，从而为学员提供整体技能，使他们成为燃料电池汽车行业的理想未来员工。本提案中所描述的研究也将有助于为AFCC的下一代燃料电池堆提供信息，因为它们将致力于2013年的产品线和未来的产品线。

The Automotive Fuel Cell Cooperation Corp. (AFCC) is developing the next generation of fuel cell stacks for their 2013 production line. Even though polymer electrolyte membrane fuel cells (PEMFCs) are promising energy conversion devices for automotive applications, the technology still faces several barriers linked to liquid water management. To provide practical water management solutions, a strong fundamental understanding of the transport mechanisms of gaseous and liquid water within the porous layers of the fuel cell are vital for designing PEMFCs that will be used at high current density operation, where high amounts of liquid water are present. In the work proposed here, AFCC is supporting a two-pronged effort to 1) develop material characterization strategies using micro computed tomography (µCT) to gain insight into the microscale structure of the porous materials employed in the fuel cell and 2) develop a pore network modeling tool that will ultimately enable AFCC to predict the liquid water fluxes and saturation states of these porous materials as a function of gaseous fuel diffusivity to the electrochemical reaction sites. Over the next two years, AFCC will collaborate with the investigator and provide the trainees with a transparent understanding of the industry-specific issues that are facing their next generation of fuel cell stacks, thus providing the trainees with the overall skill set that will make them ideal future employees for the fuel cell automotive sector. The research that is described in this proposal will also help to inform AFCC's next generation of fuel cell stacks as they work towards the 2013 product line and future product lines.