Modeling and Additive Manufacturing of Porous Electrodes for Novel High Temperature PEM Fuel Cells

拟议的研究项目旨在加强有关新型燃料电池建模和制造的知识基础。因此，管状高温聚合物电解质膜（HT PEM）燃料电池将开发，建模，制造和表征。管状HT PEM燃料电池具有将平面HT PEM燃料电池的优点（例如使用重整气体作为燃料）与从SOFC技术已知的管状设计的优点（例如，更高的功率密度和改进的效率）联合收割机结合的潜力。在拟议的研究项目范围内，将设计这种新型燃料电池，并开发合适的模拟模型。仿真模型的核心内容是分析燃料电池电极的孔隙率特性及其对燃料电池性能的影响。基于结果，将定义对孔隙率特性的要求，并用于开发管状燃料电池电极的制造路线。由于电极必须是多孔的（以允许质量传输），机械稳定的（以支持其他功能层，如膜和催化涂层）和导电的，新的增材制造技术，如选择性激光熔化（SLM）可能是一种可行的方法，以满足所研究的管状电极的制造限制。SLM基于使用激光束逐层熔化细粒金属粉末。拟议的研究项目的第二个目标是SLM技术的资格，作为一个定义的多孔管状燃料电池电极的制造路线。因此，SLM工艺参数（激光功率（PL）、扫描速度（vs）、阴影距离（hs）、层厚度（s）和激光束直径（d））以及粉末形态（粒度分布）对孔隙率特性（总孔隙率、开/闭孔隙率、孔径和分布、渗透率）的影响将被研究并用于开发经验模型。SLM制造的燃料电池电极的特点，并用于优化和验证开发的模拟模型。此外，利用适当的测试方法，如三维计算机断层扫描将允许开发增强的模拟模型，其中孔隙度特性是在微观层面上建模，而不是宏观均匀的方法。通过这种方式，可以在模拟中考虑孔隙率的性质，以更准确地预测燃料电池的性能特性。

The proposed research project aims to enhance the knowledge base regarding modeling and manufacturing of novel fuel cells. Thereby tubular high-temperature polymer electrolyte membrane (HT PEM) fuel cells will be developed, modeled, manufactured, and characterized. Tubular HT PEM fuel cells have the potential to combine advantages of planar HT PEM fuel cells such as the usage of reformat gas as fuel with the ones of tubular designs which are known from SOFC techniques (e.g. higher power density and improved efficiency). Within the scope of the proposed research project such novel fuel cells are going to be designed and suitable simulation models will be developed. Core element of the simulation model will be the analysis of porosity characteristics of the fuel cell electrodes and how this affects the fuel cell performance. Based on the results requirements on porosity characteristics will be defined and used to develop a manufacturing route for the tubular fuel cell electrodes. Since the electrodes have to be porous (to allow mass transport), mechanically stable (to support other functional layers such as membrane and catalytic coating) and electrically conductive, novel additive manufacturing technologies such as selective laser melting (SLM) may be a feasible approach to meet the manufacturing constraints of the studied tubular electrodes. SLM is based on a layer-by-layer melting of fine-grained metal powder using a laser beam. A second objective of the proposed research project is the qualification of the SLM technique as a manufacturing route for defined porous tubular fuel cell electrodes. Therefore, the influence of SLM process parameters (laser power (PL), scan speed (vs), hatching distance (hs), layer thickness (s), and laser beam diameter (d)) as well as powder morphology (grain size distribution) on porosity characteristics (overall porosity, open/closed porosity, pore size and distribution, permeability) will be studied and used to develop an empirical model. SLM-manufactured fuel cell electrodes will be characterized and used to optimize and validate the developed simulation models. In addition, the utilization of adequate test methods such as 3D computer tomography will allow the development of enhanced simulation models, in which porosity characteristics are modeled on a microscopic level instead of a macro homogenous approach. In this way the nature of the porosity can be considered in the simulation to predict the fuel cell performance characteristics more accurately.