柔性线基被动式微流体燃料电池内两相传递及电化学转化特性

Flexible thread-based passive microfluidic fuel cells，a new technology as fully passive micro fuel cells without external driving devices, utilize capillary thread-based materials to realize fluid flow and are considered as a one of the most promising alternative power sources for flexible microfluidic devices. A new flexible thread-based passive microfluidic fuel cell is proposed in this project. The electrochemical reaction coupled two-phase transport and electricity generation of the flexible thread-based passive microfluidic fuel cell will be investigated. The fluid transport characteristics in capillary thread-based materials will be visualized. The two-phase transport in capillary thread-based materials with anode or cathode electrochemical reaction will be obtained. Then, the experiments will be conducted to obtain the multi-species transport characteristics and its effects on electricity generation for flexible thread-based passive microfluidic fuel cells. Furthermore, combining with the multi-species transport model at the anode and cathode, the mathematical model for the whole fuel cell, which describes comprehensively the electrochemical reaction coupled two-phase transport characteristics and the electricity generation in flexible thread-based passive microfluidic fuel cells, will be established. Finally, the relationship between the complicated electrochemical reaction coupled two-phase transport and the cell performance could be revealed. This work will provide theoretical basis for the research and development of micro fuel cells.

柔性线基被动式微流体燃料电池是利用毛细线基材料输运液相反应物从而去除了外部驱动设备的完全被动式微型燃料电池新技术，是柔性微流体器件最有前景的替代电源之一。本项目提出柔性线基被动式微流体燃料电池的新型结构，针对其内部含有电化学反应的两相传递及产电特性开展创新性的基础科学研究，主要研究内容包括：毛细线基材料内液体输运特性；阳极/阴极侧含电化学反应边界的毛细线基材料内两相传输特性；在此基础上，开展柔性线基被动式微流体燃料电池内多组分传递及其对产电特性的影响实验，并通过阳极与阴极理论模型的耦合，最终得到一个能够全面描述柔性线基被动式微流体燃料电池内含有电化学反应的多场驱动下两相传递及产电特性的理论模型，揭示柔性线基被动式微流体燃料电池内复杂电化学反应、两相传递与产电特性之间的耦合作用机理，为微流体燃料电池的研究开发奠定理论基础。

柔性线基被动式微流体燃料电池利用毛细线基材料输运反应物，取消了传统微流体燃料电池对微量注射泵的依赖，极大地简化了系统的附件设备，提高了微流体燃料电池整个系统的功率输出，且使得系统更易集成化和微型化。本项目针对柔性线基被动式微流体燃料电池中具有复杂电化学转化的毛细材料内的液体输运、物质传递及产电的耦合机理开展研究工作,首先直接采用棉线作为输运液体的通道，对棉线的微观结构进行了表征，构建了基于碳纸及石墨棒电极的微流体燃料电池，研究了不同运行条件下棉线的输运特性及电池的产电性能；接着分别采用棉线、碳纤维及碳布构建了流道与电极一体化的微流体燃料电池，不仅简化了电池结构，还强化了传质，对一体化电极进行了物理化学表征，研究了具有一体化电极的微流体燃料电池的产电特性；然后为进一步简化结构，提出了单通道线基微流体燃料电池，采用过氧化氢同时作为燃料和氧化剂，并构建了自供能的线基过氧化氢浓度传感器；构建了柔性单通道微流体燃料电池，研究了电池在不同弯曲角度、反复弯折和高处坠落等工况下的产电特性；还制备了具有甲酸盐耐受性的非贵金属氧还原催化剂，构建了自呼吸阴极柔性单通道线基微流体燃料电池；采用格子Boltzmann方法探究了基于棉线及一体化电极的微流体燃料电池阳极耦合电化学反应的传质特性，研究了燃料浓度、流量等参数对传质及产电特性的影响；建立了基于碳纸阳极的棉线微流体燃料电池全电池理论模型，可对电池性能进行预测。项目的实施为线基被动式微流体燃料电池技术的应用和发展奠定了理论基础，具有重要的科学意义和实用价值。