Nanomanufacturing of Three-Dimensional Nanofiber-Nanoparticle Electrodes for Ultra-low Platinum Fuel Cells

如今，电动汽车是唯一的零排放汽车选择。它们要么是燃料电池供电，要么是电池供电。对于300英里行驶里程的车辆，燃料电池具有比电池高6倍的关键优势，例如，比能量高6倍（即，更低的重量功率比），比能量低6倍（即，更低的燃料重量），再加油时间快（即，更短的充电时间）。尽管汽车制造商已经设计出解决方案，克服了将燃料电池汽车推向市场的许多主要障碍，但由于所需贵金属铂电极的高成本是限制其大规模商业化的主要因素。该奖项研究了独特的纳米纤维-纳米颗粒燃料电池电极的制造，这些电极中的纳米材料-电化学关系以及它们对燃料电池性能的后续影响。该项目为燃料电池设计最优的先进纳米结构电极奠定了基础，大大降低了所需的铂，从而降低了成本。这项研究为高效低成本燃料电池的大规模商业化提供了途径，这将对社会产生重大影响，燃料电池将以更低的环境成本为汽车提供替代能源，也为固定电力提供替代能源。该项目的综合实验和建模方法来理解纳米结构电极的设计和功能，对纳米制造和电化学工程具有重大影响。推广和教育活动包括让K-12学生参与燃料电池模块技术，招募和培训实验室中代表性不足的本科生。该项目的总体目标是制造具有先进纳米级形态的电极，并了解形态对多种同步反应/传输现象的影响，从而以更高的效率和更低的成本产生燃料电池能量。具体目标是纳米制造新的可控的，组织良好的三维（3D）纳米纤维纳米颗粒电极，在超低铂含量下表现出最佳的燃料电池性能。这些新的三维纳米结构电极是通过无针静电纺丝/静电喷涂与模板辅助纳米纤维收集的新工艺制造的。本文还建立了一种新的三维燃料电池模型，用于预测三维纳米纤维-纳米颗粒电极燃料电池的性能，为电极纳米制造提供指导。准确的模型参数是通过一套全面的先进的原位和非原位实验技术，用于仔细表征和分析三维电极形态，电化学反应速率和传输性质获得的。新工艺生产的燃料电池电极具有先进的纳米级形态，克服了以前低铂负载的传统燃料电池电极严重的传输和反应限制的缺点。

Today, electric vehicles are the only zero-emission vehicle option. They are either fuel cell and battery-powered. Fuel cells have key advantages over batteries for vehicles with 300-mile driving range, e.g., 6-times higher specific energies (i.e., lower weight-to-power ratio), 6-times lower energy storage (i.e., lower fuel weight), and rapid re-fueling times (i.e., shorter recharge times). Although automakers have engineered solutions to many of the major hurdles to bringing the fuel cell vehicle to the market place, the high cost due to the required precious metal platinum electrodes is a major factor that has limited their mass commercialization. This award investigates the manufacturing of unique nanofiber-nanoparticle fuel cell electrodes, the nanomaterial-electrochemical relationships in these electrodes and their subsequent impact on fuel cell performance. This project establishes a fundamental understanding of designing optimal advanced nanostructured electrodes for fuel cells that significantly lowers the required platinum and therefore lowers their cost. This research provides pathways to mass commercialization of efficient low-cost fuel cells, which can have significant impact on society, where fuel cells will provide alternative energy at a lower environmental cost not only for automobiles, but for stationary power as well. The project's comprehensive experimental and modeling approach to understand the design and functioning of nanostructured electrodes has a significant impact on nanomanufacturing and electrochemical engineering. Outreach and education activities consist of involving K-12 students in fuel cell module technology and recruiting and training underrepresented undergraduate students in the laboratory.The overall goal of this project is to manufacture electrodes with advanced nanoscale morphologies and understand the impact of morphology on multiple simultaneous reaction/transport phenomena to generate fuel cell energy at higher efficiencies and lower costs. The specific objective is to nanomanufacture new controllable, well-organized three-dimensional (3D) nanofiber-nanoparticle electrodes that exhibit optimal fuel cell performance at ultra-low platinum contents. These new three-dimensional nanostructured electrodes are manufactured via a new process, needleless electrospinning/electrospraying with template-assisted nanofiber collection. A new three-dimensional fuel cell model is also developed to predict fuel cell performance with three-dimensional nanofiber-nanoparticle electrodes to guide in electrode nanomanufacturing. Accurate model parameters are obtained through a comprehensive set of advanced in situ and ex situ experimental techniques that are utilized to carefully characterize and analyze the 3D electrode morphology, electrochemical reaction rates, and transport properties. The new process produces fuel cell electrodes with advanced nanoscale morphologies that overcome previous shortcomings of severe transport and reaction limitations in low platinum loaded conventional fuel cell electrodes.