Mechanistic Studies of High Temperature Oxygen Electrodes with Simultaneous High Activity and Stability

同时具有高活性和稳定性的高温氧电极的机理研究

• 批准号: 1006113
• 负责人: Xiao-Dong Zhou
• 金额: $ 36万
• 依托单位: University South Carolina Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1006113&HistoricalAwards=false
• 关键词: Mechanistic; Studies; Temperature; Oxygen; Electrodes

TECHNICAL SUMMARY:Materials research for the advanced energy systems (e.g. fuel cells and batteries) has been driven by the recognition that multifunctionalities in constituent materials are needed in order to achieve higher power density, faster kinetics, and larger energy density. For instance, mixed electronic and ionic conducting oxides are used as oxygen reduction electrode - cathode. In an active cathode, both oxygen ions and electron holes move out of the electrode in a substantial flux, which creates a gradient in the electronic transference number with position inside grains that form the electrode, resulting in local oxidation or reduction. As a consequence, cation kinetic demixing takes place, along with possible phase transition, amorphorization, or even solid-state reaction. This Solid State and Materials Chemistry supported program is to investigate the evolution of electrode materials under electrochemical potential, particularly cation kinetic demixing. Of particular interest will be the electrodes based on (1) perovskite family oxides with presence of oxygen vacancies, (2) perovskite family oxides with presence of cation vacancies, and (3) Ruddlesden-Popper type complex oxides with presence of oxygen interstitials. The research concentrates on the investigation of charge exchange and transport in the presence of external loads to elucidate the role of electrochemical potential gradients on oxygen reduction NON-TECHNICAL SUMMARY:Next generation of fuel cells and batteries requires higher power, faster kinetics, and larger energy density, which necessitate the use of complex materials to achieve multifunctionalities and activity. The dichotomy is that the active constituents are often not stable; and the stable components are not very active. This project, supported by the Solid State and Materials Chemistry program in the National Science Foundation is to investigate the origin of this activity/stability conjugation. The knowledge gained in this program will be translated into design guidelines of new electrodes with simultaneously high efficiency and high performance stability for fuel cells and batteries, so that they can store more energy, recharge faster, and their performance degrades more slowly. This will be accomplished through systematically theoretical and experimental studies, along with active recruitment of four graduate/undergraduate students to build a diverse group that includes women and members of underrepresented minority groups. The students will be trained to be the future leading researchers in the area of energy materials and solid-state electrochemistry. In addition, the chemistry teachers from local high schools will be aligned with the research experience to transfer demonstrations and experiments into their classrooms, and to promote high school students to enter the science disciplines.

先进能源系统（例如燃料电池和蓄电池）的材料研究一直受到以下认识的推动：为了实现更高的功率密度、更快的动力学和更大的能量密度，需要组成材料中的多功能性。 例如，混合的电子和离子导电氧化物用作氧还原电极-阴极。 在活性阴极中，氧离子和电子空穴都以相当大的流量移出电极，这在形成电极的晶粒内部的位置处产生电子迁移数的梯度，导致局部氧化或还原。因此，阳离子动力学分层发生，沿着可能的相变、无定形化或甚至固态反应。这个固态和材料化学支持的程序是研究电极材料在电化学电势下的演变，特别是阳离子动力学分层。 特别感兴趣的是基于（1）存在氧空位的钙钛矿族氧化物、（2）存在阳离子空位的钙钛矿族氧化物和（3）存在氧空位的Ruddlesden-Popper型复合氧化物的电极。该研究集中在外部负载存在下的电荷交换和传输的调查，以阐明电化学电位梯度对氧还原的作用非技术摘要：下一代燃料电池和电池需要更高的功率，更快的动力学和更大的能量密度，这需要使用复杂的材料来实现多功能性和活性。 二分法是活性成分通常不稳定;而稳定的成分不是非常活跃。 该项目由美国国家科学基金会的固态和材料化学项目支持，旨在研究这种活性/稳定性共轭的起源。在该计划中获得的知识将被转化为新电极的设计指南，同时具有高效率和高性能稳定性的燃料电池和电池，使它们能够存储更多的能量，更快地充电，并且它们的性能下降得更慢。这将通过系统的理论和实验研究来实现，沿着积极招募四名研究生/本科生，以建立一个包括妇女和代表性不足的少数群体成员的多样化群体。 学生将被培养成为未来能源材料和固态电化学领域的领先研究人员。 此外，当地高中的化学教师将结合研究经验，将演示和实验转移到他们的课堂上，并促进高中生进入科学学科。