基于Nafion纳米棒阵列的燃料电池有序化膜电极的制备与构效关系研究

Proton exchange membrane fuel cell (PEMFC) is currently one of the popular research topics in the field of new energy transport power devices. The catalytic layer (also known as the electrode) in the current MEA (Membrane Electrode Assembly), which is the core component of PEMFC, is featured as disordering porous composite structure, however a series of critical scientific problems are presented such as strong electrochemical polarization, strong concentration polarization and short lifetime. Taking highly ordered proton conducting in the catalytic layer as breakthrough, this application proposes a new system with multiphase conducting highly ordered MEA based on Nafion nanorods array structure. In the project, controllable Nafion nanorods array will be prepared through thermal compression method and template method, and the micro and nano size effects as well as the growth mechanism of the Nafion nanorod will be investigated. Pt thin film will be loaded on Nafion nanorods by the two methods of chemical deposition and atomic layer deposition, and the relationship between microstructure and function of the electrode will be researched. The electrochemical model of the ordered MEA will be developed, and the electrochemical reaction and conducting mechanism in the Nafion nanorods array catalytic layer will be investigated. The single cell equipped with this ordered MEA will be constructed, both the electrochemical model and the mechanisms will be verificated by performance experiments of the single cell. It’s expected that new system of the ordered MEA with Nafion nanorods array is prepared, and the quantitative relationship between electrode microstructure and performance is illuminated. Moreover it provides with theoretical basis for the preparation of ordered MEA with superior performance, low cost, long lifetime, and inspires the technical development for the fabrication of the next generation ordered MEA.

质子交换膜燃料电池是目前新能源交通动力电池领域的研究热点。现有燃料电池的核心部件-膜电极的催化层为无序化的多孔复合结构，存在强电化学极化、强浓差极化和短寿命的关键科学问题。本申请以催化层中的质子导体的高度有序化为突破点，提出基于Nafion纳米棒阵列“丛林”状结构的多相传质高度有序化的膜电极新体系。通过热压法与模板法相结合的手段可控制备Nafion纳米棒阵列，研究纳米棒阵列的微纳尺寸效应及其机理；通过化学沉积法和原子层沉积法的对比方案在Nafion纳米棒上制备Pt薄层，研究电极微结构与功能之间的关系；发展该有序化膜电极的电化学模型，研究Nafion纳米棒阵列催化层内电化学反应与传质机理；组装该有序化膜电极单池，验证模型机理。预期构建出Nafion纳米棒阵列有序化膜电极新体系，揭示其构效关系，为高性能、低成本、长寿命燃料电池膜电极的制备奠定理论基础，带动下一代有序化膜电极制备技术发展。

质子交换膜燃料电池是目前新能源交通动力电池领域的研究热点。现有燃料电池的核心部件-膜电极的催化层为无序化的多孔复合结构，存在强电化学极化、强浓差极化和短寿命的关键科学问题。本项目以催化层中的质子导体的高度有序化为突破点，提出了基于Nafion纳米棒阵列“丛林”状结构的多相传质高度有序化的膜电极新体系。项目开展了四个方面的研究内容：1）Nafion纳米棒阵列的可控制备与结构物性；2）Nafion纳米棒阵列催化层的构建与表征；3）Nafion纳米棒阵列催化层内电化学反应和传质机理；4）Nafion纳米棒阵列有序化膜电极电化学性能与构效关系优化。通过4年研究攻关，项目构建出了基于Nafion纳米棒阵列的有序化膜电极，实现了电极质子、电子、气体通道的三维网络结构定向、可控设计，阐明了可控制备方法，揭示了Nafion纳米棒阵列的有序化膜电极构效关系。有序化膜电极实现了在低铂载量、低加湿下的高功率密度化发电，在发电性能指标上取得突破：在阳极铂载量为0.087±0.005 mg/cm2时，低加湿或不加湿情况下，有序化膜电极发电性能达到0.6 V @1.5 A/cm2）。项目发表了SCI 收录论文14 篇(第一标注)，申请了中国发明专利23 件。该项目为高性能、低成本、长寿命燃料电池膜电极的制备奠定了理论基础，带动了下一代有序化膜电极制备技术发展。