Collaborative Research: A New Rational Design of Functionally Graded Materials for Durable Lithium-Ion Batteries

对于远程电动汽车和大规模智能电网等许多尖端应用，对高性能和可靠的储能技术，特别是锂离子电池的需求越来越大。可靠性和可循环性是这些市场当前LIBS技术中最关键的瓶颈之一。一般来说，电极材料的成分和结构不稳定性是导致可靠性问题的最常见问题。提高电极稳定性的最新方法是使用不均匀的涂层来保护电极表面。然而，电极/涂层界面产生的内阻对性能有负面影响。本项目将研究用于下一代储能技术的LiBS中功能梯度材料的可控合成及其电化学稳定性。该项目还包括相关的课程开发、本科生研究经验以及向当地高中推广的计划。本项目旨在通过可控的表面重构来了解锂电池电极的界面稳定机理，并建立构建耐用锂电池功能梯度材料(FGM)的实验方法。该项目将使用现场同步加速器X射线表征技术来识别电池化学、配位几何和功能梯度材料涂层电极的相变行为。该项目将通过将先进的表征与电化学分析相结合，全面了解LIBS功能梯度材料的工艺-结构-性能关系。研究目标将通过以下目标实现：(1)结合多种原位和非原位电化学和光谱表征工具，了解功能梯度材料中结构/组成梯度的形成机理；(2)研究功能梯度材料的结构/组成梯度对提高LiBS耐久性的作用，了解结构/组成梯度对电极材料电学和电化学性质的影响；以及(3)了解女性生殖器切割的电极保护机制，为持久的LIB建立探索女性生殖器切割结构和成分重建的方法。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

There is an increasing demand for high-performance and reliable energy storage technologies, especially lithium-ion batteries (LIBs), for many cutting-edge applications such as long-range electric vehicles and large-scale smart grids. Reliability and cyclability are among the most critical bottlenecks in the current LIBs technologies for these markets. In general, the compositional and structural instabilities of electrode materials are the most encountered problems responsible for the reliability issues. The state-of-the-art approach to improve the electrode stability is to protect the electrode surfaces using inhomogeneous coating layers. However, the internal resistance generated at the electrode/coating-layer interface has negative effects on performance. This project will investigate the controllable synthesis and electrochemical stability of FGM in LIBs for next-generation energy storage technologies. The project also includes related course development, undergraduate research experience and outreach plans to local high schools. This project aims to understand the interfacial stabilization mechanism of lithium battery (LIB) electrodes through a controllable surface reconstruction and to establish experimental approaches for constructing functional graded materials (FGM) for durable LIBs. The project will use in-situ synchrotron X-ray characterization techniques to identify battery chemistry, coordination geometry, and phase transition behaviors in FGM coated electrodes. The project will comprehensively access the processing-structure-property relationship of FGM for LIBs by integrating advanced characterizations with electrochemical analyses. The research goals will be accomplished through the following objectives: (1) understanding the formation mechanism of structure/composition gradients in FGM by combining multiple in-situ and ex-situ electrochemical and spectroscopic characterization tools; (2) studying the roles of structure/composition gradient of FGM in improving the LIBs durability, understanding the effects of structure/composition gradients on the electrical and electrochemical properties of electrode materials; and (3) understanding the electrode protection mechanism of FGM, establishing approaches to probe the structural and compositional reconstruction of FGM for durable LIBs.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.