基于微尺度效应的微型直接甲醇燃料电池阳极气液两相传输研究

The micro direct methanol fuel cell (µDMFC) has been considered as a research focus due to the advantages of high-efficiency, environmental-friendly and easy storage of fuel. However, the investigations on µDMFC based on Microelectromechanical System (MEMS) are studied roughly. Based on micro-scale effect, the anode two-phase transport is the key factor for the critical technical breakthrough of µDMFC. In this project, a multi-physics model coupled with Micro-scale effect, Electronics, Fluid mechanics and Electrochemical is established. Based on the micro-pore characteristic, the multi-components mass and momentum transports in the anode diffusion layer are investigated to optimize the two-phase transport and enhance the output performance. Based on Lattice-Boltzmann model, the investigation on micro-scale effect of anode flow field is conducted, and the carbon dioxide emission is optimized. Based on above analysis, a µDMFC is fabricated using MEMS technology. A novel experimental investigation based on response surface method is proposed, the micro-scale effect on output voltage and two-phase visualization transport are examined to conduct model verification. This project is a novel cross-disciplinary topic, which includes MEMS, Electrochemical, New materials and New energy. The investigation is practically critical for the technical breakthrough and the portable application of µDMFC.

微型直接甲醇燃料电池（µDMFC）具有高效、环保、燃料易于储存等优点，使其成为MEMS微能源领域中的研究热点。基于MEMS技术的µDMFC研究处于萌芽阶段，揭示其内部微尺度效应下的阳极气液两相传输机制是µDMFC技术获得突破的关键科学问题。本项目拟结合微尺度学、电子学、流体力学以及电化学等建立µDMFC多物理场耦合模型，深入研究微孔特性下的阳极扩散层多组分质量和动量传输，旨在优化电池内部气液两相传质，提高µDMFC的输出特性；结合晶格-玻尔兹曼介观分析方法，对阳极流场结构的微尺度效应进行分析，优化二氧化碳气体排放机制；在此基础上，利用MEMS技术制作µDMFC，通过响应面方法实验分析不同微尺度效应下的电池输出电压和气液两相可视化传输，进行模型验证。本研究涉及到微机电系统、电化学、新材料和新能源等领域，属于多学科交叉的前沿课题，研究成果对微型燃料电池关键技术的突破和实用化具有重要意义。

微型直接甲醇燃料电池（μDMFC）具有高效、环保、燃料易于储存等优点，使其成为MEMS微能源领域中的研究热点。基于MEMS技术的μDMFC研究处于萌芽阶段，揭示其内部微尺度效应下的阳极气液两相传输机制是μDMFC技术获得突破的关键科学问题。本项目进行了微型直接甲醇燃料电池阳极扩散层传质优化，研究了阳极梯度扩散层对内部气液两相传递的影响；提出并验证了微型直接甲醇燃料电池的自适应供电方法；从仿真和实验两个方面进行了微型直接甲醇燃料电池阳极微尺度效应分析；研究了重力在甲醇阳极两相气液传输过程中的影响；同时对被动式微型直接甲醇燃料电池的阳极气液两相进行了分析与优化设计，建立了被动式μDMFC两相传质等温模型，分析了温度引起的对流机制对电池阳极气液两相传输的影响，系统分析了电池阳极CO2气泡全运动行为，并进行了可视化验证；进行了基于直接甲醇燃料电池的电路系统建模与设计研究，并利用硅胶加热垫实现直接甲醇燃料电池的热优化。本研究涉及到微机电系统、电化学、新材料和新能源等领域，属于多学科交叉的前沿课题，研究成果对微型燃料电池关键技术的突破和实用化具有重要意义。