聚合物电解质膜燃料电池硅基阵列模型电极传质行为研究

Under the urgent situation of energy and environment, a revolution of technologies of electric energy will come to the human public. As one of the most clean and efficient substitutes for the energy devices, polymer electrolyte membrane fuel cells (PEMFC) have still suffered from obstacles in issues of fabrication cost, cell performance and durability. Among the crucial factors that determine these issues of PEMFC, processes within electrode, i.e. mass transport, play important roles for the recognizing and optimizing the electrode structures. However, the complexity of traditional electrodes hampers the further study of these processes. To focus on the mass transport behaviors in electrode, this program will carried out the fabrication and characterization of a modeling electrode based on ultra-ordered rigid silicon nanoarrays. With the help of modern electrochemical methods and in-situ spectroscopy/microscopy measurement, the relationships between structural parameters and mass transport properties will be studied. Further, the physical models of mass transport in ordered structures will also be constructed by computational simulations with molecular dynamic methods and computational fluidic dynamic methods. We believe that these works will elucidate the intrinsic mechanism of mass transport within nanostructures of fuel cell electrodes, and may provide theoretical instructions for the design and fabrication of advanced fuel cell electrodes with reduced cost and enhanced performance and durability.

伴随着日益紧迫的资源与环境压力，人类社会必将迎来新一轮的电能源技术革命。聚合物电解质膜燃料电池（PEMFC）作为一种清洁、高效的替代电源技术，其商业化进程仍面临性能、成本、寿命的诸多挑战。燃料电池电极中包括物质传递在内的电极过程及其行为本质，是影响电极性能至关重要的因素。但由于电极结构的复杂性与尺度的微纳化，燃料电池中电化学环境的微观流体物质传递研究仍面临着严峻的困难与挑战。本项目将针对电极微纳尺度的传质行为，基于刚性硅基纳米阵列材料，开展具有精确有序结构参数模型电极的控制制备，利用电化学表征方法结合原位谱学显微手段，研究模型电极中气液传质孔道尺寸、形状、曲折系数等结构参数对物质传递系数与传质通量的影响机制，并进一步通过分子动力学模拟以及计算流体力学方法阐释电极中物质传递对电极性能影响的物理模型，为燃料电池电极结构的设计与构建提供理论依据，进而降低燃料电池制备成本，提高其性能与寿命。

本项目基于电能源的洁净利用与转化，以聚合物电解质膜燃料电池技术为应用导向，在理论上实现了建立一系列结构简单有序的阵列模型电极，通过考察电极中传质通道尺寸、形貌、密度、长度、表面亲疏水性等关键参数对气液传质的影响机制，并结合理论计算结果，阐释并揭示聚合物电解质膜燃料电池电极中，微纳尺度范围内流体的物质传递的行为本质。在技术上本项目通过研究电极结构-性能的内在相互联系，实现对聚合物电解质膜燃料电池电极结构设计制备的指导，进一步降低燃料电池电极成本、提高电极性能与寿命。