Dealloying Under Conditions of Significant Solid-State Mass Transport

大量固态传质条件下的脱合金

• 批准号: 1306224
• 负责人: Karl Sieradzki
• 金额: $ 50.69万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1306224&HistoricalAwards=false
• 关键词: Dealloying; Under; Conditions; Significant; Solid

TECHNICAL SUMMARY:This research program examines the kinetics of dealloying and morphology evolution in alloy systems for which the solid-state mass transport processes of lattice and grain-boundary diffusion are significant at ambient temperature. The major control parameters in the work will be the alloy composition, grain size of the polycrystalline hosts, particle size in the particulate hosts and temperature. The electrochemical parameters to be varied include dissolution under conditions of fixed voltage (chronoamperometry) and fixed current (chronopotentiometry). This will allow for the separate determination of the dependence of morphology on the applied electrochemical potential and dealloying rate. In order to examine these issues a combined experimental and computational approach is used. The alloy systems under study are Li-Sn, Li-Pb and Li-Cd. These host metals and similar ones are currently being considered as anode reservoirs in future lithium-ion batteries and have been chosen for study since they represent variations in the host crystal structures, tetragonal, face-centered cubic and hexagonal close-packed, respectively, and have a rich history with abundant thermodynamic and kinetic data available. Electrochemical methods are used to produce the alloys, measure dealloying rates and determine associated solid-state mass transport rates. Dealloying morphologies are examined using focused ion-beam machining and scanning electron microscopy. Kinetic Monte Carlo simulations are used to model morphology evolution in dealloying as a function of the electrochemical potential and dealloying rate.NON-TECHNICAL SUMMARY:This research examines morphology evolution during dealloying of low melting point lithium alloys. Such alloys are currently being considered for use in advanced lithium-ion batteries in which the dealloying process corresponds to that occurring during discharge of these battery systems. The findings likely to emerge from this research will significantly impact research in energy storage and particularly the development of new materials for future batteries. As this country considers its energy options, it will need people with combined expertise in electrochemistry and materials science to address current and future energy technologies. The scope of research in this program will afford undergraduate and graduate students the opportunity for fundamental training in an integrated materials electrochemistry laboratory environment. More generally in the area of education and training, the PI will be developing a new undergraduate course in the "materials science of electrochemical energy storage and production," and the course together with all materials will be available for colleagues to use via the worldwide web.

技术摘要：该研究计划研究了合金系统中的交易和形态演化的动力学，在环境温度下，晶格和晶粒结构扩散的固态质量传输过程很明显。工作中的主要控制参数将是合金组成，多晶宿主的晶粒尺寸，颗粒宿主中的粒度和温度。要多样化的电化学参数包括固定电压（计时度计量法）和固定电流（计时度计）的溶解。这将允许单独确定形态对应用的电化学潜力和交易速率的依赖性。为了检查这些问题，使用了组合的实验和计算方法。研究的合金系统是LI-SN，LI-PB和LI-CD。这些宿主金属和类似的金属目前被视为未来锂离子电池中的阳极储层，并且已经被选为研究，因为它们代表了宿主晶体结构的变化，分别是四方，面部中心和六角形的封闭式，并且具有丰富的热力学和动力学数据，并具有丰富的历史。电化学方法用于生产合金，测量交易速率并确定相关的固态质量运输速率。使用聚焦的离子梁加工和扫描电子显微镜检查了Deadloying形态。动力学蒙特卡洛模拟用于模拟形态的发展，以与电化学潜力和交易速率的函数进行交易。没有技术摘要：本研究研究了低熔融点锂合金的交易过程中的形态演化。目前正在考虑将这种合金用于高级锂离子电池中，其中交易材料工艺与这些电池系统放电期间发生的合金相对应。这项研究可能会出现的发现将极大地影响能源存储的研究，尤其是开发未来电池的新材料。当这个国家考虑其能源选择时，它将需要具有电化学和材料科学专业知识的人来解决当前和未来的能源技术。该计划的研究范围将为本科和研究生提供基础培训的机会，以进行集成材料电化学实验室环境。在教育和培训领域中，PI将在“电化学能源存储和生产的材料科学”中开发新的本科课程，并且该课程与所有材料一起可以供同事通过全球网络使用。