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：非技术概述插层化学，即离子进入和离开材料结构的过程，是商业锂离子电池工作原理的核心。这一概念也是新兴技术的核心，包括电致变色、海水淡化、热开关和电阻开关材料。在电池技术方面，氧化物材料长期以来一直是嵌入材料的首选。然而，它们受到与离子嵌入相关的退化的影响，这种退化会在电池长时间充放电时缓慢恶化电池性能，从而限制电池的寿命。在NSF材料研究部固态和材料化学计划的支持下，合成了一类新的插层材料，该材料使用氯原子代替主体结构中的氧。研究了离子在卤化物材料中的可逆性，并与在氧化物材料中的可逆性进行了比较，得出了这类新型插层材料的结构-性能关系。该项目为设计更坚固的锂离子电池插层材料提供了新的途径。此外，作为该项目的一部分，还组织了外联活动，以接触服务不足的社区，并为有潜力进一步发展美国劳动力的本科生提供教育机会。第二部分：技术综述这项研究得到了美国国家科学基金会材料研究部固态和材料化学计划的支持，其目的是揭示影响碱性阳离子电化学嵌入过渡金属卤化物的因素，以便开发下一代锂离子或钠离子电池技术。为此，波士顿学院的首席研究员和他的研究小组开展了一项实验研究，将新型含锂或含钠的过渡金属卤化物的合成与控制其电化学(去)插层的物理性质的测量相结合。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性阳离子(De)插层，同时避免破坏性的结构转变，这些结构转变困扰着从高电位氧化物中提取锂或钠。通过绘制控制层状卤化物氧化还原化学的化学图谱，这项工作试图为配体的极化率、大小和电负性如何改变层状材料的氧化还原性质奠定基础。合成了新的介稳多晶型，通过比较它们的结构特征和电化学响应与热力学更稳定的多晶型，揭示了层状卤化物插层之间存在的层内和层间相互作用的竞争。结合电学和磁学测量，结果被综合以找出阳离子如何在过渡金属层状卤化物中引起层间和层内相互作用之间的竞争。在这项工作中收集的方法和知识有助于确定具有可调电子性能的有希望的插层材料。总而言之，这项工作促进了用于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。通过参与为8-12年级代表不足和服务不足的学生提供服务的外展计划，以及通过邀请本科生研究人员参与该项目，研究工作得到了补充。该奖项反映了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。