Novel synthesis and characterization of intermediate temperature solid oxide fuel cells

燃料电池通过电化学反应将化学能直接转化为电能。由于这种能量的直接电化学转换，燃料电池提供了高效、环保的能源，并被定位为满足未来能源需求的解决方案之一。燃料电池基本上需要由离子传导电解质分隔的阳极和阴极。不同类别的燃料电池根据所使用的电解质在很宽的温度范围内运行。据能源部报告，固体氧化物燃料电池（SOFC）因其高预期能源效率而引起了人们的兴趣。人们对将 SOFC 的温度要求降低到至少 600 800 ℃ 的中间温度范围同时仍保持高效率非常感兴趣。这些中温 (IT) SOFC 需要新材料和替代结构才能在较低温度下实现高电化学效率。如何实现这一目标是问题所在。来自芝加哥伊利诺伊大学的研究人员 Christos Takoudis、Gregory Jursich、Robert Klie 和 Alan Zdunek，以及来自伊利诺伊州阿贡国家实验室的 Jeffrey Miller 相信，他们的团队和他们将采用的程序正是在新型 IT SOFC 方面取得进展所需要的。实现较低温度可操作性的一个关键是设计 SOFC 的阳极、阴极和电解质层的厚度较小，并精确控制各层的化学成分。使用目前安装在阿贡实验室先进光子源的独特原子层沉积/化学气相沉积 (ALD/CVD) 混合反应器来制造厚度从接近块状微米层到原子状纳米层的复杂金属氧化物，PI 将开发和控制 IT-SOFC 的热和电化学特性，以成功实现降低温度的可操作性。人们必须知道化学合成的是什么，因此PI将在ALD/CVD沉积、反应和热转变条件下利用X射线吸收和X射线衍射来更好地理解和控制最终微纳米材料结构的合成过程。这种独特的实验装置将使人们能够了解从宏观到微观化学的电化学、催化和热性能趋势，这是迄今为止无法实现的。此外，该设备将允许 PI 在同一反应器中作为一个沉积过程制造所有三个组件，从而产生原子级明确的界面区域，并将三个组件作为一个整体系统进行评估。这一新燃料电池计划的概念很简单：在一个反应​​器中制作受控化学成分的薄层，这样界面也受到控制，并且大大提高了创建可行的 IT SOFC 的机会。使用正确的分析设备来了解已制成的产品是成功的关键。 PI 打算将这一技术项目与现有的研究生招募模式结合起来，其中包括伊利诺伊大学芝加哥分校 (UIC) 现有的研究生招募模式，其中包括来自代表性不足群体的研究生。还计划开展潜在的外展教育计划，以向本科生和高中生传播科学。

Fuel cells provide direct conversion of chemical energy into electrical energy by means of electrochemical reactions. Because of this direct electrochemical conversion of energy, fuel cells offer efficient, environmentally desirable energy sources, and are targeted as one of the solutions for future energy needs. A fuel cell basically requires an anode and a cathode separated by an ion-conducting electrolyte. Different classes of fuel cells operate over a wide range of temperature depending on the electrolyte used. Solid oxide fuel cells (SOFCs) have generated interest due to their high expected energy efficiency as reported by the Department of Energy. There is tremendous interest in lowering the temperature requirements of SOFCs to at least an intermediate temperature range of 600 800 ºC while still maintaining high efficiency. These intermediate temperature (IT) SOFCs require new materials and alternate structures to achieve high electrochemical efficiency at lower temperatures. How to achieve this is the problem.Investigators Christos Takoudis, Gregory Jursich, Robert Klie, and Alan Zdunek from the University of Illinois at Chicago, along with Jeffrey Miller from Argonne National Laboratories in Illinois believe their team and the procedures they will employ are exactly what are required to make progress on a new class of IT SOFCs. One key to achieve lower temperature operability is to engineer the SOFCs with smaller thickness for each of the anode, cathode and electrolyte layers and with precise control over the chemical compositions of the layers. Using a unique atomic layer deposition/chemical vapor deposition (ALD/CVD) hybrid reactor currently installed at the Advanced Photon Source at Argonne Labs to create complex metal oxides with thicknesses varying from near bulk-like micron layers to atomic-like nanometer layers, the PIs will develop and control the thermal and electrochemical properties of the IT-SOFCs to achieve successful reduced temperature operability. One must know what has been chemically crafted, so the PIs will use X-ray absorption and X-ray diffraction during ALD/CVD deposition, reaction and thermal transformation conditions to better understand and control the synthesis process of the final micro-nano material structures. This unique experimental set-up will allow hitherto unavailable understanding of electrochemical, catalytic and thermal property trends from the macroscopic to microscopic chemistries. In addition, the equipment will allow the PIs to fabricate all three components within the same reactor as one deposition process, resulting in atomically well-defined interfacial regions and evaluation of the three components as an integral system. The concept for this new fuel cell program is straightforward: make thin layers of controlled chemical composition in one reactor so the interfaces are also controlled, and the chances of creating a viable IT SOFC are vastly improved. Use of the correct analytical equipment to know what has been made is key to success. The PIs intend to couple this technical program with the existing modes of enlisting of graduate students, including those from under-represented groups, already in place at UIC. Potential outreach educational programs are planned as well to spread the science to undergraduates and high school students.