Investigation of Degradation Mechanisms in Layered Oxide Cathodes for Na Ion Batteries

钠离子电池层状氧化物阴极降解机制的研究

• 批准号: 1410936
• 负责人: Hailong Chen
• 金额: $ 46万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1410936&HistoricalAwards=false
• 关键词: Investigation; Degradation; Mechanisms; Layered; Oxide; Investigation; Degradation; Mechanisms; Layered; Oxide

Non-Technical AbstractLithium ion batteries are widely used as power sources in portable electronics and electric cars. However, the scarcity of lithium potentially limits the application of lithium ion batteries in future. Sodium ion battery is a promising alternative energy storage technology due to its potential to compete with lithium ion batteries in all performance categories, such as energy and power densities. More importantly, sodium is naturally abundant and sodium ion batteries can be manufactured at much lower cost. However, sodium ion batteries suffer from poor cycle life, largely due to the degradation and failure of the cathode. This research studies the degradation mechanism of the layered oxide cathode materials at bulk and microscopic scales. With support from the Solid State and Materials Chemistry Program in the Division of Materials Research, the goal is to understand the structural evolution of the cathode materials during battery cycling and to develop means of mitigating electrode degradations for improving the cycle life of sodium ion batteries. The project involves close collaborations between experiment and modeling. Research opportunities are provided to train both graduate and undergraduate students. The project also involves the course development for high school students. Technical AbstractSodium ion battery is a promising energy storage device with low cost. However, the severe degradation of cathodes can drastically limit the cycle life of sodium ion batteries. The project aims to elucidate the degradation mechanisms in the cathode of sodium ion batteries using the layered metal oxides as model systems. The research hypothesis is that the mechanical degradations are primarily responsible for the capacity fade and accordingly poor cycle stability in layered oxide cathodes. Model compounds, such as sodium manganese oxide, are synthesized and electrochemically tested in half cells. In situ X-ray diffraction is used to study the structural change of the bulk cathode materials, and in situ transmission electron microscopy is used to observe the microscopic structural changes. Based on the experimental observations and analyses, multiscale chemomechanical models are developed to rationalize and predict the degradation mechanism of the cathodes. This research not only enables the design of high performance electrode materials for sodium ion battery with long cycle life, but also develops novel in situ experimental techniques to advance the fundamental research of solid state chemistry.

非技术抽象升离离子电池被广泛用作便携式电子和电动汽车中的电源。但是，锂的稀缺性可能限制了将来锂离子电池的应用。钠离子电池是一种有希望的替代储能技术，因为它有可能与所有性能类别（例如能量和功率密度）中的锂离子电池竞争。更重要的是，钠自然丰富，并且可以以更低的成本制造钠离子电池。但是，钠离子电池的周期寿命差，主要是由于阴极的降解和失败。该研究研究了在散装和微观尺度上分层氧化物阴极材料的降解机制。在材料研究部中固态和材料化学计划的支持下，目标是了解电池循环过程中阴极材料的结构演化，并开发减轻电极降解的方法，以改善钠离子电池的循环寿命。该项目涉及实验与建模之间的密切合作。提供研究机会来培训研究生和本科生。该项目还涉及高中生的课程开发。技术摘要离子电池是一种有前途的储能设备，成本低。但是，阴极的严重降解可以大大限制钠离子电池的循环寿命。该项目旨在阐明使用分层金属氧化物作为模型系统的钠离子电池阴极中的降解机制。研究假设是，机械降解主要是造成能力褪色的，因此分层氧化物阴极中的循环稳定性较差。模型化合物（例如锰氧化钠）在半细胞中合成并进行电化学测试。原位X射线衍射用于研究散装阴极材料的结构变化，原位透射电子显微镜用于观察显微镜结构变化。基于实验观测和分析，开发了多尺度化学力学模型，以合理化和预测阴极的降解机制。这项研究不仅可以设计具有较长循环寿命的钠离子电池的高性能电极材料，而且还可以开发出新颖的原位实验技术来推进固态化学的基本研究。