基于多尺度多场耦合模型的微流体燃料电池多孔电极构效关系研究

Microfluidic fuel cell (MFC) has been identified as one of the most promising alternative power sources for portable electronics. Yet, its performance is limited by the insufficient mass transfer of reactants to the electrode active sites. In this project, multi-scale and multi-field coupling modeling and simulations will be performed to study the structure-property relationship between the microstructre and the mass transfer of the porous electrode in MFC. A micro-scale model will be developed first by the lattice Boltzmann method, the mass transport mechanism in the micropores of the porous electrode will be studied, and the relationships between the microstructures and the mass transport behavior of the porous electrode material will be derived. Then, a multi-field coupling macro-scale model will be established by the finite element method, the coupling schemes of different physicalchemical processes will be analyzed and the effect of the mass transport behavior on the cell performance will be elucidated; After that, a multi-scale model will be built up by combination of the results from the above two models, and the interaction among the porous electrode microstructure, the mass transport process and the cell performance will be investigated. Based on the results, porous electrode microstructure control will be performed to enhance the mass transport process and boost the cell performance. Results of this project will enrich the basic theories of fuel cell and meanwhile provide guidance in developing novel porous electrode materials and improving cell performance of MFC.

微流体燃料电池是便携式电子设备最有前景的替代电源之一，但电极活性中心上传质受限的问题限制了其电池性能。本项目拟通过多尺度多场耦合建模方法研究这类燃料电池多孔电极微结构与电极内部传质过程间的构效关系。采用格子玻尔兹曼方法建立多孔电极微结构模型，研究电极孔隙内的物质传输机理，揭示多孔电极微结构及其变化对电极内部传质过程的影响规律；采用有限元法建立燃料电池多孔耦合宏观模型，研究传质过程与其它物理化学过程间的耦合作用机理，明确多孔电极内部传质过程对其电池性能的影响规律；对接两种模型的模拟数据，建立多尺度多场耦合模型，分析多孔电极微结构与电极内部传质过程间的构效关系；在此基础上，探索通过多孔电极微结构调控，强化电极活性中心上的物质传输，同时增大电池输出功率与燃料利用率的方法。本项目有助于丰富和完善燃料电池领域的基础理论，为指导开发新型多孔电极材料、提升微流体燃料电池性能提供科学依据。

微流体燃料电池是便携式电子设备最有前景的替代电源之一，但电极活性中心上传质受限的问题限制了其电池性能。本项目通过多尺度多场耦合建模方法，研究了多孔电极微结构与电池内部传质过程及电池性能间的构效关系；通过定量对比多孔电极结构优化与电化学改性在电池性能提升中的作用，明确了多孔电极结构优化的重要地位；通过多参数敏感性分析，指出阳极比表面积是决定电池性能的关键因素；通过深入分析多孔电极内部电化学反应速率的分布规律，提出了不同操作条件下微流体燃料电池的性能提升方案，并探讨了高流速下实现高燃料利用率对电池几何设计、电极材料及操作参数的要求，分析了非对称电池设计与操作在对流型微流体燃料电池中的可行性；在此基础上，对微流体燃料电池的反应液输送系统进行了优化，提出了多种新型微流体燃料电池结构，并对相关研究方法与思路在其他多种类型能量转化与存储装置中的应用做了初步探究，进一步丰富了研究成果。