RII Track-4: Developing and Investigating Organic-Inorganic Hybrid Ultrathin Solid Electrolytes with NREL for Lithium Ion Batteries

随着锂离子电池（LIB）市场的不断扩大，电池可靠性和安全性的重要性不断上升。LIB中商业使用的有机液体电解质由于其高挥发性和易燃性而仍然是一个巨大的安全问题。固态电解质因其不燃性、防泄漏性和抗枝晶生长造成的损坏性而作为潜在的替代品引起了人们的极大关注。有两种主要类型的具有互补性质的固体电解质：固体聚合物电解质（SPE）和无机固体陶瓷电解质（伊势）。本项目计划开发具有层压双层结构的伊势/SPE混合电解质膜，并研究其伊势/SPE界面性质以及这些性质如何影响锂离子传输和导电性。该项目的成果将大大推进具有纳米级工程结构和性能的固体电解质的设计和制造知识，以实现更安全的LIB。通过该计划建立的尖端技术培训和实践经验以及合作将直接使PI受益？UL Lafayette在混合电解质方面的持续研究计划，大大增强了UL Lafayette的研究能力。SPE具有制备工艺简单、柔韧性好等优点，但受到离子电导率低、热稳定性差、抗氧化性差等因素的制约。伊势具有相对高的离子电导率和高的热稳定性，但柔性非常低。考虑到SPE和伊势的互补性质，先前已经努力开发具有本体结构或伊势/SPE层压多层构造的填料的SPE和伊势复合电解质。已经发现SPE/伊势界面性质是锂离子转移路径和导电性的关键影响因素。从这项工作中很好地理解伊势/SPE界面行为将为实际LIB应用的固体混合电解质材料的设计和开发提供指导。在这个项目中，一个大的界面面积的层压双层配置将被用作伊势/SPE电解质界面研究的模型，因为填料-散装型电解质有太多复杂的界面相互作用，以满足目的。影响电解质性能的另外两个主要因素包括膜厚度和膜均匀性。该项目将利用两种技术制造工艺（空气控制电喷雾和磁控溅射）的独特组合，不仅显著降低了电解质膜厚度，提高了膜的均匀性，而且还允许根据应用灵活地制备不同类型的固体电解质。例如，直接沉积在电极上的固体电解质（对于3D电池特别重要）或独立的薄电解质膜。该项目的成果和科学发现对基础知识的进步和应用技术的发展都具有重要意义。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标准进行评估，被认为值得支持。

Nontechnical DescriptionAs the market for lithium ion batteries (LIBs) keeps expanding, the importance of battery reliability and safety continues to rise. Commercially used organic liquid electrolytes in LIBs remain a huge safety issue due to their high volatility and flammability. Solid-state electrolytes have attracted great attention as the potential replacement due to their nonflammability, leakproof feature, and resistance to damage caused by dendrite growth. There are two main types of solid electrolytes with complementary properties: solid polymer electrolytes (SPE) and inorganic solid ceramic electrolytes (ISE). This project plans to develop ultrathin ISE/SPE hybrid electrolyte films with laminated bilayer configuration and to study their ISE/SPE interface properties and how these properties influence lithium ion transport and conductivity. The outcomes of this project will greatly advance the knowledge of design and fabrication of solid electrolytes with nanoscale engineered structures and properties for safer LIBs. The training and hands-on experience on cutting-edge technologies and the collaborations established via this program will directly benefit the PI?s continuing research plan on hybrid electrolytes and greatly enhance the research capacity of UL Lafayette. Technical DescriptionSPE have the advantages of simple fabrication process and good flexibility but are inhibited by low ionic conductivity, low thermal stability, and poor oxidation resistivity. ISE have relatively high ionic conductivity and high thermal stability but very low flexibility. Given the complementary properties of SPE and ISE, there have been prior efforts to develop SPE and ISE composite electrolytes with either filler in bulk structure or ISE/SPE laminated multi-layer configuration. It has been found that SPE/ISE interface properties are key influencers of the lithium ion transfer path and conductivity. A good understanding of ISE/SPE interfaces behavior from this work will provide guidance on the design and development of solid hybrid electrolytes materials for practical LIBs application. In this project, a laminated bilayer configuration with one large interface area will be used as a model for the ISE/SPE electrolyte interface study since filler-bulk type electrolytes have too many complicated interface interactions to fulfill the purpose. Two other dominant factors that impact electrolyte performance include film thickness and film evenness. This project will utilize a unique combination of two technical fabrication processes (air-controlled electrospray and magnetron sputtering) that not only significantly lowers the electrolyte film thickness and improves film evenness, but also allows the flexibility to prepare different types of solid electrolytes based on the application?s specific need, such as directly deposited solid electrolyte on electrodes (particularly important for 3D batteries) or free-standing thin electrolyte films. Results and scientific discoveries from this project are of significant meaning for both fundamental knowledge advancement and applied technology development.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.