多级毛细梯度复合流场气液分相输运的微型甲醇燃料电池研究

Micro direct methanol fuel cell (μDMFC) has been considered as a hot spot in the field of Power MEMS due to its benefits such as high energy capacity, high efficiency and low emission. However, with the significant shrinkage of the flow field dimension, performance of the μDMFC has been limited by capillary block in flow channels during mixed phase, gas-liquid transportation. Base on the findings in our previous researches, a new μDMFC flow field design concept with the function of gas-liquid separative transportation, using multilevel gradient capillary structures, is proposed in this project. The mechanism of gas-liquid separative transportation in this gradient capillary structure, as well as the design methodologies of the corresponding flow field are to achieved by combining theoretical analysis, numerical simulations and prototype experiments. Impacts of the geometrical parameters and surface property of the gradient capillary structure on the gas-liquid separative efficiency will also be revealed. Finally, the new concept flow field is to be fabricated and verified by using MEMS technics. This project is an intersectional frontier project which involves in the field of mechanics, materials, fluid and new energies. Results of this project will provide important progresses in Power MEMS technologies.

微型直接甲醇燃料电池（μDMFC）具有高比能、高效率、无污染等独特优势，是PowerMEMS领域的研究热点。随着μDMFC流场尺寸的大幅减小，反应物和生成物气液混合输运中的毛细阻塞限制了电池性能的进一步提高。本项目将在前期工作基础上，针对这一瓶颈问题提出基于多级毛细梯度结构原理，实现气液分相输运的μDMFC流场设计新思路。结合理论分析、数值计算和原型试验方法，探明毛细梯度微结构中气-液物种的分相输运机理；研究阴、阳极微流场气液分相输运结构几何参数与表面参数的设计方法，获得多级毛细梯度复合流场结构参数及其各级匹配关系对气液分相输运效能的影响规律。最后，采用MEMS工艺实现毛细梯度复合流场结构的制备和验证。本项目研究涉及机械、材料、流体、新能源等领域，是典型的多学科交叉前沿课题，研究成果将对PowerMEMS技术发展起重要推动作用。

微型直接甲醇燃料电池（μDMFC）具有高比能、高效率、无污染等独特优势，是PowerMEMS 领域的研究热点。随着μDMFC 流场尺寸的大幅减小，反应物和生成物气液混合输运中的毛细阻塞限制了电池性能的进一步提高。针对这一瓶颈问题，本项目开发出基于毛细梯度结构实现气液分相输运的μDMFC 新型流场板；结合数值计算和原型试验，探明了局域化毛细结构对电池阴、阳两极物种分相输运控制的机理和规律；开发出在金属和聚合物基底上制备极端润湿表面的新方法，并成功应用于μDMFC制造上；研究了新型流场布局和结构参数对电池性能的影响规律，阐明了流场板结构和表面能属性与电池输出特性之间的构效关系；采用本项目开发的毛细梯度结构阳极流场板，可将阳极混合流体沿程压降最高降低49%，电池功率密度最高提升92%；毛细梯度结构阴极流场板可将阴极水淹导致的功率衰减率降低3.6倍，取得了显著效果。 在项目资助下，共发表学术论文14篇，其中SCI收录9篇（含JCR TOP期刊论文2篇，IF6.0以上1篇、IF2.0-4.0共6篇,SCI他引36次，单篇最高18次），EI收录11 篇，授权国家发明专利3项，培养博士生1人，硕士生14人（毕业10人），获辽宁省自然科学学术成果一等奖、大连市自然科学优秀学术论文一等奖和中国微米纳米技术学会年度优秀论文奖各1项。