Fine tuning of structural and physical properties of transition metal halides by electrochemical intercalation

通过电化学插层微调过渡金属卤化物的结构和物理性质

• 批准号: 2326843
• 负责人: Alexis Grimaud
• 金额: $ 45万
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-12-01 至 2026-11-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2326843&HistoricalAwards=false
• 关键词: Fine; tuning; structural; physical; properties

PART 1: NON-TECHNICAL SUMMARY Intercalation chemistry, the process of ions moving in and out of a materials structure, lies at the center of how commercial Li-ion batteries work. The concept also is at the core of emerging technologies, including electrochromics, desalination, thermal switching and resistance switching materials. Regarding battery technology, oxide materials have been the intercalation materials of choice for a long time. Nevertheless, they suffer from degradations associated with ion intercalation that slowly deteriorate battery performance upon prolonged charge and discharge of the battery which limits the battery’s lifetime. For this project, which is supported by the Solid State and Materials Chemistry Program in NSF’s Division of Materials Research, a new class of intercalation materials using chloride atoms, in place of oxygen, in the host structure, is synthetized. The reversibility of ions intercalation in halide materials is studied and compared with that in oxide materials, drawing structure-property relationship for this novel class of intercalation materials. The project provides new avenues to design more robust intercalation materials for Li-ion batteries. Additionally, outreach activities are organized as part of this project to engage with underserved communities, and educational opportunities are provided for undergraduate students which has the potential to develop further the US workforce. PART 2: TECHNICAL SUMMARY The objective of this research, which is supported by the Solid State and Materials Chemistry Program in NSF’s Division of Materials Research, is to reveal the factors governing the electrochemical intercalation of alkali cations into transition metal halides, such that a future generation of Li- or Na-ion battery technologies can be developed. To this end, the principal investigator and his research group at Boston College carry out an experimental study combining the synthesis of novel lithium- or sodium-containing transition metal halides with measurements of the physical properties that govern their electrochemical (de)intercalation. The central hypothesis guiding this work is that layered halides can offer a fast alkali cation (de)intercalation while avoiding damaging structural transitions that plague the extraction of lithium or sodium from oxides at high potential. By mapping the chemical landscape that governs the redox chemistry of layered halides, this work seeks to lay the fundamental understanding to how ligand polarizability, size and electronegativity modify the redox properties of layered materials. Novel metastable polymorphs are synthetized and, by comparing their structural features and electrochemical response with that of more thermodynamically stable ones, competition existing between intra- and inter-layer interactions for intercalated layered halides can be revealed. Combined with electrical and magnetic measurements, the results are integrated to find out how cations intercalation impart the competition existing between inter- and intra-layer interactions in transition metal layered halides. Methodologies and knowledge gathered in this work serves to identify promising intercalation materials with tunable electronic properties. Collectively, this work advances redox chemistry of transition metal halides for rechargeable batteries and paves the way towards the development of new halide compounds. The research efforts are complemented by participating to outreach program serving underrepresented and underserved students in grade 8-12, and by engaging undergraduate student researchers in the project.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.

第 1 部分：非技术摘要 插层化学是离子移入和移出材料结构的过程，是商用锂离子电池工作原理的核心，该概念也是新兴技术的核心，包括电致变色、就电池技术而言，氧化物材料长期以来一直是首选的嵌入材料，然而，它们会遭受与离子嵌入相关的降解，导致电池性能在长时间充电和充电后缓慢恶化。电池放电限制了电池的使用寿命。该项目由美国国家科学基金会材料研究部的固态和材料化学项目支持，这是一种在主体中使用氯原子代替氧的新型插层材料。研究了卤化物材料中离子嵌入的可逆性，并与氧化物材料中的可逆性进行了比较，为这类新型嵌入材料绘制了结构-性能关系。此外，作为该项目的一部分，还组织了外展活动，以吸引服务不足的社区，并为本科生提供了教育机会，这些机会有潜力进一步发展美国劳动力。 2：技术摘要 这项研究得到了 NSF 材料研究部固态和材料化学项目的支持，其目的是揭示控制碱金属阳离子电化学嵌入的因素。为此，波士顿学院的首席研究员和他的研究小组进行了一项结合新型锂或钠合成的实验研究。含过渡金属卤化物并测量控制其电化学（脱）插层的物理性质。指导这项工作的中心假设是层状卤化物可以提供快速的碱金属阳离子（脱）插层，同时避免困扰的破坏性结构转变。通过绘制控制层状卤化物氧化还原化学的化学图谱，这项工作旨在对配体极化性、尺寸和电负性如何改变层状材料的氧化还原特性奠定基础。合成了亚稳态多晶型物，通过将其结构特征和电化学响应与热力学更稳定的多晶型物进行比较，可以发现插层层状卤化物的层内和层间相互作用之间存在的竞争结合电学和磁学测量，将结果整合起来，以找出阳离子插层如何影响过渡金属层状卤化物中层间和层内相互作用之间存在的竞争，这项工作中收集的方法和知识有助于识别有前途的插层材料。总的来说，这项工作推进了可充电电池的过渡金属卤化物的氧化还原化学，并为开发新的卤化物化合物铺平了道路。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。 8-12 年级的学生，以及让本科生研究人员参与该项目。