SBIR Phase I: Nano Processing of High Temperature Ceramic Oxide Thermoelectric Materials for Enhanced Performance

这个小企业创新研究（SBIR）第一阶段项目将开发一种新颖的、具有成本效益的加工和制造路线，以生产由纳米（40纳米）颗粒组成的高温陶瓷氧化物热电材料。研究表明，将热电材料的晶粒尺寸减小到100纳米以下，可使热阻和整体热电性能提高40%。所涉及的技术挑战是在所需的加工步骤中保持正确的粉末成分和烧结晶粒尺寸低于40纳米。火花等离子烧结（SPS）技术将晶粒生长限制到最小，使烧结陶瓷的晶粒尺寸保持在100纳米以下，从而保留了所有增强材料的性能。该项目将评估加工参数对热电粉末物理性能的影响，包括粒度、表面积、杂质增益、生坯和烧结密度、晶粒尺寸和最终微观结构。将评估所得粉末的热电性能，包括塞贝克系数、直流电导率、导热系数和ZT。在后续的第二期项目中，将示范商业上可行的制造工艺，以便大规模生产。该项目更广泛的影响/商业潜力将是在高温（800摄氏度）下工作的热电纳米材料的可用性，具有增强的热电性能。随着能源资源的节约和相关的环境问题变得越来越重要，社会对利用热电装置从废热中发电的兴趣也越来越大。热电技术可以在许多专门的应用中发挥作用，但一直受到效率相对较低和材料成本较高的阻碍。目前的材料还存在生产可扩展性问题。一种新的低成本、高温、高性能因数的热电材料是满足商业需求的必要条件。在该项目中开发的材料将通过允许在高温下以相对较低的预期低生产成本（低于3美元/瓦）收集废物能源，从而增加市场采用。这些材料的潜在早期采用者包括玻璃工业、钢铁制造商和汽车工业。根据最近的研究，每年仅在玻璃行业就浪费了价值近3亿美元的能源。据估计，这些材料在汽车上的市场价值超过10亿美元。这种相同的材料加工技术可以适用于电池和燃料电池技术的高离子导体以及其他陶瓷工业材料的未来应用。

This Small Business Innovation Research (SBIR) Phase I project will develop a novel and cost-effective processing and manufacturing route to produce high-temperature ceramic oxide thermoelectric materials comprised of nanosized ( 40 nm) grains. Research has shown that a reduction in grain size below 100 nanometers in thermoelectric materials results in an increase in thermal resistance and overall thermoelectric performance by up to 40%. The technical challenge involved is to maintain the correct powder composition and the sintered grain size below 40 nm throughout the required processing steps. The spark plasma sintering (SPS) technique limits grain growth to a minimum, such that grain size of the sintered ceramic remains below 100 nanometers, thus preserving all of the enhanced material properties. This project will evaluate the effects of processing parameters on physical properties of the thermoelectric powder, including particle size, surface area, impurity gain, green and sintered density, grain size and final microstructure. The thermoelectric properties of the resulting powder will be evaluated, including Seebeck coefficient, dc conductivity, thermal conductivity, and ZT. A commercially viable manufacturing process will be demonstrated for scale up to large quantities in the follow-on Phase II project. The broader impact/commercial potential of this project will be the availability of thermoelectric nanomaterials operating at high temperatures ( 800 C), with enhanced thermoelectric properties. As the conservation of energy resources and associated environmental concerns become more critical, societal interest in utilizing thermoelectric devices to generate electricity from waste heat has grown. Thermoelectrics can function in many specialized applications, but have been hindered by a relatively low efficiency and high material costs. Current materials also have production scalability concerns. A new low-cost, high-temperature, high figure-of-merit thermoelectric material is necessary to satisfy commercial demands. The materials to be developed in this project will enable increased market adoption by allowing waste energy harvesting at high temperatures with a relatively low expected low cost of production (under $3/watt). Potential early adopters of these materials include the glass industry, steelmakers, and the automobile industry. According to recent studies, there is almost $300 million worth of wasted energy per year in the glass industry alone. The estimated market for these materials in vehicles is more than $1 billion. This same material processing technology can be adapted for future applications in high ionic conductors for battery and fuel cell technologies, and other ceramic industrial materials.