High Energy Density, High Thermal Conductivity Latent Heat Storage using Inorganic Nanocomposites

本项目探索使用无机纳米复合材料作为热能储存的介质。能量密度和充放电时间是该领域的两个重要指标。这个项目的智力价值在于，它可以潜在地同时在两个度量标准中带来巨大的改进。本项目中的纳米复合材料由嵌入金属相变纳米颗粒的固体无机基体组成。这些复合材料的常见储热类似物是嵌入有机相变材料（如石蜡）的固体聚合物基体。这个项目吗?纳米复合材料的设计导致更高的体积能量密度，因为金属具有比有机相变材料高得多的聚变焓。由于无机材料的导热系数比聚合物高得多，这种纳米复合材料的设计还可以加快充放电时间。使用金属纳米粒子的另一个好处是，它们的熔化温度与尺寸有关。这意味着这些纳米复合材料的热储存温度与化学成分并不是不可分割的联系，可以是一个灵活的设计变量。此外，由于无机材料具有优异的热稳定性，这些纳米复合材料可以在聚合物基复合材料无法达到的温度下工作。为了研究这些复合材料的储热潜力，将测量不同组成、纳米颗粒尺寸和纳米颗粒体积分数的纳米复合材料的熔化温度、熔化焓和导热系数。还将进行热循环实验，以测试这些材料的稳定性和耐久性。这些纳米复合材料将使用液相化学合成，这允许基质材料的变化和对纳米颗粒大小、形状、组成和体积分数的优雅控制。这种制造技术对复合材料微观结构的精确控制将使相变和储热材料设计规则的基础研究成为可能。该项目更广泛的影响是，其尚未开发的纳米复合材料概念可以显着提高储热材料的性能；因此，它可以改变热能储存应用的广度和范围。在大规模生产中，这种纳米复合材料概念可以改善太阳能热发电和建筑热管理的热储存。在小型制造规模上，这种纳米复合材料概念可以通过淬火瞬态功率尖峰来改善电子产品的热管理。该项目还包括一项针对多个教育层次的全面外联计划。该计划：(1)通过在教室里进行热能和相关主题的互动现场演讲，吸引K-12学生。(2)设计纳米胶体合成实验模块，并将其纳入社区大学课程。

CBET-1236656PI: Robert WangThis project explores the use of inorganic nanocomposites as a medium for thermal energy storage. Energy density and charging/discharging time are two very important metrics for this field. The intellectual merit of this project is that it can potentially lead to large improvements in both metrics simultaneously. The nanocomposites in this project consist of a solid inorganic matrix with embedded metallic phase change nanoparticles. The common thermal storage analogue to these composites is a solid polymer matrix with embedded organic phase change materials (e.g. paraffin). This project?s nanocomposite design leads to higher volumetric energy densities because metals have much higher enthalpies of fusion than organic phase change materials. This nanocomposite design also leads to faster charging/discharging times because inorganic materials have much higher thermal conductivities than polymers. An additional benefit of using metallic nanoparticles is that their melting temperature is size-dependent. This means that the thermal storage temperature of these nanocomposites is not inextricably linked to chemical composition and can be a flexible design variable. Furthermore, since inorganic materials have excellent thermal stability, these nanocomposites can operate at temperatures inaccessible to polymer-based composites. To investigate the thermal storage potential of these composites, the melting temperature, enthalpy of fusion, and thermal conductivity will be measured for nanocomposites of varying composition, nanoparticle size, and nanoparticle volume fraction. Thermal cycling experiments will also be done to test the stability and durability of these materials. These nanocomposites will be synthesized using solution-phase chemistries, which allow variation of the matrix material and elegant control over nanoparticle size, shape, composition, and volume fraction. The precise control over composite microstructure of this fabrication technique will allow fundamental studies on phase change and materials design rules for thermal energy storage. The broader impacts of this project are that its unexplored nanocomposite concept could significantly improve the performance of thermal storage materials; hence it could change the breadth and scope of thermal energy storage applications. On large manufacturing scales, this nanocomposite concept could improve thermal storage for solar thermal power generation and buildings thermal management. On small manufacturing scales, this nanocomposite concept could improve electronics thermal management by quenching transient power spikes. This project also includes a comprehensive outreach plan that addresses multiple education levels. This plan: (1) Engages K-12 students via interactive on-site presentations in their classrooms that focus on thermal energy and related topics. (2) Designs a laboratory module on colloidal nanoparticle synthesis for incorporation into curriculum at the community college level.