Thermal Transport in Dynamically Disordered Materials with Frustrated Energy Landscape

可充电全固态电池已成为小型便携式电子产品的重要动力，也对电网规模的能量存储感兴趣。这些电池最紧迫的挑战之一是过热，这通常是由充电和放电过程中移动的离子引起的。了解这些材料中的传热过程对于解决电池中的过热问题和提高热电能量转换的性能至关重要。 传统的理论不能处理具有显著离子运动的材料。该项目旨在阐明伴随和竞争的热量和离子输运不太固体材料，如电池和快速离子热电。通过该项目获得的知识将使结构和材料的新设计能够满足废热回收，电池，储氢，燃料电池和太阳能电池板的广泛技术需求。该项目还将为本科生和研究生的传热课程开发新的课程材料。最近，动态无序材料已经成为巨大功能系统的新型构建模块，形成了一个明智的平台，可以研究声子子晶格和离子传导子系统之间独特的能量交换机制。该项目的新奇通过对一类新材料的热传输机制的基本探索来体现，该材料将联合收割机有序的结晶亚晶格和动力学无序的离子作为一个整体，迄今为止还没有被材料物理学家严格解决。紧密相连的原子模拟和相关的方法开发，包括构建准确的原子间的潜力来描述沮丧的能源景观，提出了为此目的的一种方法。这个项目的挑战在于现有的计算方法的失败，虽然传统的完美晶体，甚至无定形固体成熟。这个项目的结果将是具有根本意义和技术利益的动态无序材料的更广泛的背景下。该项目还将促进代表性不足和少数民族学生参与研究，为工程专业学生提供对他们未来职业至关重要的跨学科专业知识和前沿知识，并履行为科学技术培养高素质劳动力的使命。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查进行评估，被认为值得支持的搜索.

Rechargeable all-solid-state batteries have become instrumental in powering small, portable electronics and are also of interest to grid-scale energy storage. One of the most pressing challenges of those batteries is overheating, which is often caused by moving ions during charging and discharging. Understanding the heat transfer process in these materials is critical for addressing the overheating problem in batteries and improving performance of thermoelectric energy conversion. The conventional theory fails to treat materials with significant movement of ions. This project aims to elucidate concomitant and competing heat and ion transport in not-quite-solid materials such as batteries and fast ionic thermoelectrics. The knowledge gained through this project will enable novel design of structures and materials for broad technological needs in waste heat recovery, batteries, hydrogen storage, fuel cells, and solar panels. The project will also develop new course materials for undergraduate and graduate heat transfer courses.Recently, dynamically disordered materials have emerged as new types of building blocks for immense functional systems, which form a judicious platform to study unique energy exchange mechanism among a phonon sublattice and an ion-conducting subsystem. The novelty of this project manifests itself through a fundamental exploration of the thermal transport mechanisms of a new class of materials that combine ordered crystalline sublattices and kinetically disordered ions as a whole, which has thus far not been rigorously addressed by material physicists. Closely linked atomistic simulations and pertaining methodology development, including constructing accurate interatomic potential to describe the frustrated energy landscape, are proposed as an approach to this end. The challenge of this project lies in the conceivable failure of the existing computational approaches, although mature for traditional perfect crystals and even amorphous solids. The outcome of this project will be of both fundamental significance and technological interest to the broader context of dynamically disordered materials. The project will also promote the engagement of underrepresented and minority students in research, equip the engineering students with interdisciplinary expertise and frontier knowledge crucial to their future careers, and fulfill the mission to prepare high quality workforce for science and technology.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.