金属支撑直接内重整固体氧化物燃料电池反应与传递机理

The metal-supported solid oxide fuel cell (MS-SOFC) utilizes a porous alloy layer to support the whole cell, which is a promising novel kind of fuel cell. In this project, the metal-supported SOFC is used to implement the direct internal reforming (DIR) of natural gas. The influence of the design parameters and operation conditions on the internal reforming products, the carbon deposition, the temperature distribution as well as the electrochemical performance are studied. The coupling mechanism of the homogeneous and heterogeneous reactions as well as the carbon deposition mechanism are explored. Then, a multi-physics elementary reaction level model is developed by incorporating the homogeneous chemical reactions, the heterogeneous chemical reactions on the surfaces of both the catalytic metal-support layer and the anode Ni, the charge transfer reactions at the triple phase boundary and the heat-transport and mass-transport processes within the fuel cell. The reaction rate controlling steps and the coupling effects of the reaction and transfer processes of the metal-supported DIR SOFC are clarified by integrating the simulation and experimental tests. The proposed project can be the theoretical foundation for both the configuration design and the performance optimization of the metal-supported DIR SOFC.

金属支撑固体氧化物燃料电池（Metal-supported Solid Oxide Fuel Cell, MS-SOFC）采用多孔金属作为SOFC的支撑体，是一类具有重要应用前景的新型燃料电池。本项目采用金属支撑SOFC实现天然气的直接内重整，揭示金属支撑层设计参数与操作条件参数对内重整产物、阳极积碳、温度分布与电池电化学性能的影响规律，阐明电池阳极侧均相化学反应与非均相化学/电化学反应的耦合作用机制以及积碳机理。综合考虑均相基元反应、金属支撑催化层与阳极Ni表面非均相基元反应、三相界面处电荷转移基元反应以及金属支撑SOFC的传热、传质特性，建立多物理场耦合的基元反应机理模型。明确金属支撑直接内重整SOFC阳极侧反应速率控制步骤，掌握电池单元反应与传递过程的耦合机制，获得电池构型设计参数及操作条件优化策略，为电池构型的开发及性能改进提供理论基础。

金属支撑固体氧化物燃料电池采用多孔金属作为SOFC的支撑体，是一类具有重要应用前景的新型燃料电池。本项目掌握了金属支撑SOFC的制备流程，采用热等静压法-等离子喷涂技术完成了纽扣式/管式金属支撑SOFC的制备，获得了操作条件对金属支撑SOFC性能的影响规律。全面考虑SOFC内部化学/电化学反应与热量传递、质量传递、电荷传导等多种传递过程的耦合作用，建立从一维电极模型到三维电堆模型的多尺度SOFC稳态/动态分析模型，成功应用于鉴别金属支撑SOFC内部反应与传递过程耦合机制。金属支撑的引入有效促进了SOFC中的内部重整反应和电化学反应的耦合作用，可降低电池内部的温度梯度并提升电化学性能。开发基于真实三维电堆模型的SOFC-热电联供系统分析模型，同步获得系统特性与SOFC电堆内部温度、组分、流速等重要参数分布，建立了电池微观层面反应传递过程与宏观层面电堆/系统性能直接对应的桥梁。本项目研究成果，可为发展天然气为燃料的SOFC技术及其分布式供能系统提供重要的理论基础。