Collaborative Research: Selective Extraction of Lithium from Seawater using Structurally Modified Metal Oxide Layered Materials

锂是包括锂离子电池在内的许多现代储能系统的重要组成部分。随着清洁能源的转型，对这种关键矿物的需求正在迅速增长，以目前的速度，很快就会超过锂的供应。陆地锂源（如矿石和卤水）的锂产量可能不足以满足预期需求。海水是一种有前途的、丰富的锂资源，但从海水中回收锂在技术上具有挑战性。目前的回收方法受到萃取能力低、难以从海水中发现的化学性质相似的离子中选择性分离锂离子以及操作成本高的限制。伍斯特理工学院（WPI）的滕晓伟教授和路易斯维尔大学（UL）的巴德里·纳拉亚南教授旨在通过开发新型氧化锰层状材料，利用电化学方法从海水中选择性提取锂，从而解决这些技术限制。研究人员将把材料的合成和表征方法与电化学性能评估和原子计算模型结合起来，揭示材料结构如何影响阳离子的传输行为。其研究方法是化学工程、材料科学、计算化学和电化学的交叉点，为本科生和研究生的跨学科培养提供了宝贵的机会。该项目还将支持外联活动，以增加高中学生和教师的科学参与。该项目旨在了解掺杂剂、缺陷化学、离子水化和离子传输之间的相互作用，以及结构修饰的二氧化硅（MnO2）基层状材料在选择性海水锂提取中的作用。该研究方法将结合湿化学合成、电化学实验、operando x射线表征和各种原子模拟技术，以确定二氧化锰基电极的关键特性(a)有利于锂离子的插入，同时拒绝较大的竞争离子（如钠、镁），(b)促进锂离子传输动力学，同时抑制竞争离子的扩散。(c)在宽工作电压窗下实现高容量锂离子提取，同时避免水解离。将考察二氧化锰的结构、组成、缺陷浓度/分布、掺杂剂的性质、层间距离以及合成条件。来自STEM领域代表性不足群体的本科生将被招募到WPI和UL实验室参与研究。两间实验室将展开暑期本科生交换计划，以扩大学生接触新的技术概念和研究环境。高中科学教师将被邀请完成一个为期七周的暑期研究项目，以开发动手科学学习的教学方法和材料，并提高学生的科学素养和参与度。该奖项反映了美国国家科学基金会的法定使命，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。

Lithium is a vital component of many modern energy storage systems, including lithium-ion batteries. Demand for this critical mineral is growing rapidly, coinciding with the clean energy transition, and will soon outstrip lithium supplies at the current rate. Lithium production from land-based lithium sources (e.g., ore and brine) may be insufficient to meet the anticipated demand. Seawater is a promising, plentiful source of lithium, but recovering lithium from seawater is technologically challenging. Current recovery methods are limited by low extraction capacity, difficulty selectively separating lithium ions from chemically similar ions found in seawater, and high operation costs. Professor Xiaowei Teng at Worcester Polytechnic Institute (WPI) and Professor Badri Narayanan at the University of Louisville (UL) aim to address these technological limitations by developing new classes of manganese oxide layered materials for the selective extraction of lithium from seawater using electrochemical methods. The investigators will integrate materials synthesis and characterization methods with electrochemical performance assessment and atomistic computational modeling to reveal how the material structure affects the cation transport behavior. The research approach lies at the interface of chemical engineering, materials science, computational chemistry, and electrochemistry, providing a valuable opportunity for cross-disciplinary training of undergraduate and graduate students. The project will also support outreach activities to increase the scientific engagement of high-school students and teachers. The project aims to understand the interplay between dopants, defect chemistry, ion-hydration, and ion transport in structurally modified birnessite (MnO2)-based layered materials on selective lithium extraction from seawater. The research approach will combine wet-chemistry synthesis, electrochemical experiments, operando X-ray characterization, and a variety of atomistic simulation techniques to identify the critical characteristics of MnO2-based electrodes that (a) favor insertion of lithium ions while rejecting the larger competing ions (e.g., sodium, magnesium), (b) promote kinetics of lithium-ion transport while suppressing diffusion of competing ions, and (c) enable high-capacity lithium-ion extraction at wide operation voltage windows while avoiding water dissociation. MnO2 structure, composition, defect concentration/distribution, nature of dopants, and interlayer distance, as well as synthesis conditions, will be examined. Undergraduate students from underrepresented groups in STEM will be recruited to participate in the research at the WPI and UL laboratories. A summer undergraduate student exchange program between the two laboratories will be initiated to broaden students’ exposure to new technical concepts and research environments. High-school science teachers will be invited to complete a seven-week summer research program to develop hands-on science learning pedagogy and materials and improve scientific literacy and engagement among their students.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.