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。由于这种直接的电化学能量转换，燃料电池提供了高效的、环保的能源，并被作为未来能源需求的解决方案之一。燃料电池基本上需要一个由离子导电电解液隔开的阳极和阴极。根据所使用的电解液的不同，不同类别的燃料电池可以在很大的温度范围内运行。根据能源部的报告，固体氧化物燃料电池(SOFC)由于其预期的高能效而引起了人们的兴趣。在保持高效率的同时，将SOFC的温度要求降低到至少600 800°C的中间温度范围是非常有兴趣的。这些中温(IT)SOFC需要新的材料和替代结构来在较低的温度下实现高的电化学效率。如何实现这一点是个问题。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，以及伊利诺伊州Argonne国家实验室的Jeffrey Miller认为，他们的团队和他们将采用的程序正是在新一类IT SOFC上取得进展所需的。实现低温可操作性的一个关键是为阳极、阴极和电解液层设计厚度较小的SOFC，并对这些层的化学成分进行精确控制。使用目前安装在Argonne实验室高级光子源的独特原子层沉积/化学气相沉积(ALD/CVD)混合反应器来创建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的热和电化学性质，以实现成功的降温操作。人们必须知道什么是化学加工的，所以PI将使用在ALD/CVD沉积、反应和热转变条件下的X射线吸收和X射线衍射来更好地了解和控制最终微纳米材料结构的合成过程。这一独特的实验装置将使人们能够从宏观到微观了解电化学、催化和热性质的趋势。此外，该设备将允许PI在一个沉积过程中在同一反应器内制造所有三个组件，从而实现原子上定义良好的界面区域，并将三个组件作为一个完整的系统进行评估。这一新燃料电池计划的概念很简单：在一个反应堆中制造受控化学成分的薄层，以便界面也得到控制，创造出可行的IT SOFC的机会大大提高。使用正确的分析设备来了解所制造的是什么是成功的关键。PIS打算将这一技术方案与UIC已有的招收研究生的现有模式相结合，包括那些来自代表性不足群体的研究生。还计划了潜在的外展教育项目，以向本科生和高中生传播这项科学。

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.