PECASE: Nanoscale Assembly Approaches Toward High Performance Micro Fuel Cells

PECASE：实现高性能微型燃料电池的纳米级组装方法

• 批准号: 0954985
• 负责人: Andre Taylor
• 金额: $ 40万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0954985&HistoricalAwards=false
• 关键词: PECASE; Nanoscale; Assembly; Approaches; Toward

0954985TaylorFuel cells were once championed as viable alternatives to existing battery technology for energy storage. However, such hopes have not been realized due to poor assembly of the catalyst interface contributing to the meager performance of these devices. The research proposed here will use a new, integrated approach, combining the advantages of top down (microfabrication) with bottom up (electrostatic assembly) to obtain high-performance fuel cells. The work will integrate high-performance nanomaterials into a CMOS microfabricated fuel cell architecture, resulting in self-assembled nanomaterial/polyelectrolyte composites through water-based processing methods integrated into a silicon-based, microstructured fuel cell architecture. Direct alcohol fuel cells (DAFCs) are of particular interest because of the high power density of renewable liquid fuels such as ethanol. The proposed fuel cell architecture will be achieved by etching microfluidic channels into a silicon-based substrate with integrated electrodes, heaters, and temperature sensors. The substrate will serve as a platform for the layering of the catalyst nanomaterials (e.g. decorated carbon nanotubes, polymers) on top of a monolithic, open face, fuel cell architecture. Exploration of the assembly methods as well as a comprehensive assessment of materials suitable for this approach would transform this field by creating next-generation power sources that can readily be integrated with electronic devices. Intellectual MeritThe research is novel because it combines the advantages of top-down microfabrication with bottom-up electrostatic assembly to obtain unique fuel cell device structures. Furthermore, this research is potentially transformative because this new fabrication approach and its resulting device architectures have significant potential to make the breakthroughs needed to achieve high-performance alkaline fuel cells that convert ethanol, a renewable liquid fuel, directly to electricity for use in vehicles. Although the specific work will focus on alkaline direct ethanol fuel cells, the systems generated should prove to be applicable to hydrogen and bio-fuel cell systems. The research plan incorporates top-down, bottom-up, and integrative approaches. First, in the top-down approach, an integrated monolithic microstructured fuel cell design will maximize bulk and surface micromachining processing capabilities originally developed for integrated circuits and MEMs devices. Design rules will be derived to capture operating conditions (e.g., flow rates and temperatures) and design parameters (e.g., channel length, electrode design, and active area) to maximize the performance of an individual microstructured fuel cell. Second, in the bottom-up approach, nanomaterials that exploit the advantage of superior electrocatalytic activity at both the anode and cathode will be employed, using carbon nanotubes decorated with transition metal catalysts. Third, in the integrative approach, the electrostatic layer-by-layer (LBL) assembly method will be used to generate ultrathin films (on top of the monolithic fuel cell) through the alteration of polycationic and anionic polymer/nanomaterial systems. This alteration will enable the nanoscale manipulation of thin film composition and the creation of molecular level blends that would be difficult to produce using conventional fuel cell assembly methods. Parameters (e.g. ionic strength and polyion composition) will be varied to generate a highly tuned membrane electrode assembly interface built directly on top of the integrated silicon based platform.Broader Impact In addition to the traditional interdisciplinary training of graduate and undergraduate students, web-based distance learning approaches will be used to reach a larger, broader audience of students from under-represented groups through a two-stage collaborative pipeline. The first stage is the development of electrochemistry modules for a Detroit High School chemistry class using YouTube, and the second is to have undergraduates at Armstrong Atlantic State University lead the design and development of a spray coat layer-by-layer deposition machine aimed to decrease the fabrication time of functional thin films used in the research. Other activities include development of modules for a course entitled Microelectrochemical Systems.

燃料电池曾一度被认为是现有电池技术的可行替代品。然而，由于催化剂界面组装不良导致这些设备性能不佳，这种希望尚未实现。这里提出的研究将采用一种新的集成方法，结合自顶向下（微加工）和自底向上（静电组装）的优势来获得高性能燃料电池。这项工作将把高性能纳米材料集成到CMOS微制造燃料电池结构中，通过水基加工方法将自组装纳米材料/聚电解质复合材料集成到硅基微结构燃料电池结构中。由于可再生液体燃料（如乙醇）的高功率密度，直接酒精燃料电池（DAFCs）受到特别关注。提出的燃料电池架构将通过将微流体通道蚀刻到集成电极、加热器和温度传感器的硅基衬底上来实现。该基板将作为催化剂纳米材料（如装饰碳纳米管、聚合物）分层的平台，覆盖在单层、开放式的燃料电池结构之上。对组装方法的探索以及对适合这种方法的材料的全面评估将通过创造易于与电子设备集成的下一代电源来改变这一领域。本研究的新颖之处在于，它结合了自顶向下的微加工和自底向上的静电组装的优点，获得了独特的燃料电池器件结构。此外，这项研究具有潜在的变革性，因为这种新的制造方法及其产生的设备架构具有巨大的突破潜力，可以实现高性能碱性燃料电池，将乙醇（一种可再生液体燃料）直接转化为车辆使用的电力。虽然具体的工作将集中在碱性直接乙醇燃料电池上，但所产生的系统应该被证明适用于氢和生物燃料电池系统。研究计划采用自顶向下、自底向上和综合方法。首先，在自上而下的方法中，集成的单片微结构燃料电池设计将最大限度地提高最初为集成电路和MEMs器件开发的批量和表面微加工处理能力。设计规则将用于捕获操作条件（例如，流量和温度）和设计参数（例如，通道长度，电极设计和有效面积），以最大限度地提高单个微结构燃料电池的性能。其次，在自下而上的方法中，利用在阳极和阴极都具有优越电催化活性的纳米材料，使用装饰有过渡金属催化剂的碳纳米管。第三，在集成方法中，通过改变聚阳离子和阴离子聚合物/纳米材料体系，将使用静电逐层（LBL）组装方法生成超薄膜（在单片燃料电池的顶部）。这种改变将使薄膜组成的纳米级操作和分子级混合物的创造成为可能，这将很难用传统的燃料电池组装方法生产。参数（如离子强度和多离子组成）将发生变化，以产生高度调谐的膜电极组装界面，直接构建在集成硅基平台之上。更广泛的影响除了对研究生和本科生进行传统的跨学科培训外，基于网络的远程学习方法将通过两阶段的协作管道，用于接触更多、更广泛的来自代表性不足群体的学生。第一阶段是利用YouTube为底特律高中的化学课开发电化学模块，第二阶段是让阿姆斯特朗大西洋州立大学的本科生领导设计和开发一种喷涂层逐层沉积机，旨在减少研究中使用的功能薄膜的制造时间。其他活动包括为一门名为“微电化学系统”的课程开发模块。