CAREER: Novel Engineered Nanostructured Complex Oxide Thermoelectric Materials for High Temperature Power Generation

非技术描述：工业发电厂、涡轮发动机和汽车的废气产生大量的热量，这些热量以非生产性的方式释放到环境中，从而浪费大量的热能。改善我们能源基础设施和电力基础的可持续性的一个潜在方法是利用具有直接将温差转换为电能的能力的热电发电机来回收余热。氧化物材料，如新开发的无毒钴酸钙(CCO)，由于其在高温下在空气中的稳定性，在热电发电机中的应用前景特别好。目前开发热电氧化物面临的挑战是提高能量转换效率，而目前热电材料的能量转换效率低于传统的热电材料。这个职业项目探索了提高热电氧化物能量转换效率所必需的关键纳米结构科学和工程工艺。该项目的教育方面包括培养研究生和本科生，并扩大未被充分代表的学生群体对材料科学和工程研究的参与。为了向更广泛的社会介绍热电材料和能源可持续发展的新概念，高中教师通过西弗吉尼亚大学现有的教师知识促进研究经验项目参与了该项目。高中教师正在将他们的实验经验收集在一本期刊上，为他们的课堂设计和开发先进材料的能源应用教材。技术细节：目前开发热电氧化物的挑战是提高转换效率，目前这一效率低于传统的热电材料。这个职业项目的目标是通过纳米结构工程方法改善氧化物CCO的能量转换性能。该项目通过实验合成/测量和透射电子显微镜，探索了在CCO中使用工程纳米包裹体的新的掺杂和热传输定制策略。特别是，该项目利用包括掺杂剂在内的不同缺陷和CCO中的纳米级夹杂的协同组合来增强电传输性能，同时将导热系数降至最低。该项目的成功完成有望确定提高氧化物陶瓷能量转换效率所需的关键纳米结构工程工艺，这些工艺可用于高温应用，如化石能源发电厂和汽车中的应用。虽然上述研究将对热电氧化物的发展产生直接影响，但从研究中获得的陶瓷材料纳米结构工程的基础知识将对许多其他陶瓷系统有用。这些系统包括用于燃气轮机的氧化物耐火材料和氧化物热障涂层，它们可以从工程设计的导热系数降低中受益匪浅。这个职业项目非常注重本科生和研究生水平的研究和教育的整合，开展用于能源收集的先进陶瓷和纳米科学和技术的尖端研究。

NON-TECHNICAL DESCRIPTION: Industry power plants, exhaust from turbine engines and automobiles generate an enormous amount of heat that is unproductively released into the environment, thereby wasting vast amount of thermal energy. A potential way to improve the sustainability of our energy infrastructure and electricity base is through waste heat recovery using thermoelectric power generators that possess the ability to directly transform temperature differentials into electrical power. Oxide materials, such as newly developed non-toxic calcium cobaltite (CCO) are particularly promising for applications in thermoelectric power generators because of their stability in air even at high temperatures. The current challenge for developing thermoelectric oxide is to improve the energy conversion efficiency, which is currently lower than that of the conventional thermoelectric materials. This CAREER project explores the key nanostructure science and engineering processes necessary to improve the energy conversion efficiency of thermoelectric oxide. The educational aspect of this project involves training both graduate and undergraduate students, and broadening the participation of underrepresented student groups in materials science and engineering research. To introduce the novel concept of thermoelectric materials and energy sustainability to the broader society, high school teachers are involved in the project through the existing Teachers Research Experience for the Advancement of Knowledge program at West Virginia University. The high school teachers are collecting their lab experiences in a journal, and designing and developing teaching materials about advanced materials for energy application for their classrooms.TECHNICAL DETAILS: The current challenge for developing thermoelectric oxide is to improve the conversion efficiency, which is currently lower than that of the conventional thermoelectric materials. The objective of this CAREER project is to improve the energy conversion properties of oxide CCO, through nanostructure engineering approaches. This project explores novel doping and thermal transport tailoring strategies in CCO with engineered nanoscale inclusions, through experimental synthesis/measurement and transmission electron microscopy. In particular, this project utilizes the synergetic combination of different defects including dopants, and nanoscale inclusions in CCO to enhance the electrical transport properties and minimize thermal conductivity simultaneously. The successful completion of this project is expected to identify the key nanostructure engineering processes necessary to improve the energy conversion efficiency of oxide ceramics that could be utilized for high temperature applications, such as applications in fossil energy power plants and automobiles. While the above research will have direct impact on the development of thermoelectric oxide, the fundamental knowledge on the nanostructure engineering of ceramic materials gained from the research will be instrumental to many other ceramic systems. Those systems include oxide refractory materials and oxide thermal barrier coatings for gas turbines that can benefit significantly from engineered thermal conductivity reductions. This CAREER project has a strong focus on integration of research and education at both the undergraduate and graduate levels, for carrying out cutting-edge research in advanced ceramics for energy harvesting, and nanoscale science and technology.