低温环境下新型质子交换膜燃料电池超疏水流道工作机制研究

Proton Exchange Membrane Fuel Cell（PEMFC）is a new kind of energy technology to convert the chemical energy to electricity directly, which has the advantages of green environmental protection, efficiency productivity, low noise, etc. Therefore, PEMFC has a widely application fields. However, PEMFC will met the problems at low temperature environment such as the difficulty to start even fail to start, and performance degradation. A novel superhydrophobic flow channel is proposed in this project. the superhydrophobic surface is covered on the flow channels of the metallic bipolar plates surface, the bioinspired method is applied to the branch structure of the PEMFC's flow channels. Combined the theoretical, numerical and experimental methods, the discipline of the water and thermal distributions is studied at sub-freezing environment. The drainage mechanism of the superhydrophobic channel at low temperature environment is explored. the cold-start performance of the superhydrophobic channel is investigated and the influence factors are analyzed by the variant control method. the main parameters are optimized to realize the self-start function. This research is expected to facilitate the theoretical significance and engineering guide for the working state of the PEMFC under sub-freezing temperature and provide the theoretical and technical guidance for the PEMFC cold-start mechanism under sub-freezing temperatures.

质子交换膜燃料电池（缩写为PEMFC）是一种能够将燃料的化学能直接转化为电能的新能源技术，具有绿色环保、产能高效、噪音低等优点，应用前景广阔。然而，PEMFC在低温环境下工作时面临启动困难甚至失败、持久性衰减等问题。本项目提出一种新型超疏水流道，对金属双极板流道表面进行超疏水处理，采用仿生学方法将分支结构应用于PEMFC流道结构中；理论、数值模拟与实验相结合研究低温环境下PEMFC水热分布规律，揭示低温环境PEMFC超疏水流道排水机理；分析超疏水流道的燃料电池在低温环境下的启动性能，采用控制变量法分析影响PEMFC低温启动的主要因素，对主要参数进行优化以实现PEMFC在低温环境下的自启动。本项目研究成果对于PEMFC在低温环境下工作的基础研究具有重要的理论意义和工程指导价值，为揭示PEMFC低温启动机理提供理论指导与技术支撑。

通过四年的研究工作，基本完成了项目目标。通过模型分析、数值模拟和实验相结合的方法研究了在不同的环境温度下改变燃料电池工作参数对电池冷启动性能的影响；研究了微通道壁面粗糙度对液体流动和传质特性的影响规律；完成了超疏水型质子交换膜的改性，提升了质子交换膜燃料电池的低温冷启动性能。拓展研究了聚四氟乙烯膜的制备方法，并测试了其超疏水性能和机械性能。