Diametric Extremes in the Ionic Conductivity of Mixed Glass Former Solid Electrolytes

混合玻璃前体固体电解质离子电导率的直径极值

• 批准号: 1304977
• 负责人: Steve Martin
• 金额: $ 51万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1304977&HistoricalAwards=false
• 关键词: Diametric; Extremes; Ionic; Conductivity; Mixed

NON-TECHNICAL DESCRIPTIONThe sun, a very large source of untapped energy, has a cyclic pattern of night and day. Therefore, energy storage systems are required and batteries are promising technologies being considered if problems of safety, high cost, and low efficiency can be resolved. Given the size of energy storage systems required, very low cost and earth abundant sodium batteries are being actively researched. Sodium batteries today, however, must operate at 300 C because the battery separator, a solid electrolyte, has a low Na+ ion conductivity and this causes such batteries to be inefficient, unsafe, and expensive. For these reasons, it is important to better understand Na+ ion motion in the solid state so that newer better conducting solid electrolytes can be developed. In this project, new glassy solid electrolytes are being studied that can be made very inexpensively with high Na+ ion conductivities. In particular, Martin's group is examining new ternary glasses based upon two network formers (e.g., silicon, boron, or germanium) that form a highly cross-linked arrangement of chemical bonds. These particular glasses are being studied because it has been found that in some combinations of two glass formers the Na+ ion conduction increases dramatically whereas for other combinations the Na+ ion motion decreases significantly. By studying these two different systems and their opposite behaviors, it will be possible to learn more about how Na+ ions conduct through solids and help develop new sodium batteries based upon better solid electrolytes. TECHNICAL DETAILSNa+ ions doped into a glass former can have very high conductivities when the chemistry is optimized. A rare coincidence of high ionic conductivity and improved physical and electrochemical properties of glassy solid electrolytes can be obtained by mixing two glass formers, B and P, for example, at a constant fraction of Na+. Such optimized mixed glass former glassy solid electrolytes based upon earth abundant Na may be candidates from which next generation cheaper, safer, and more efficient large grid-scale batteries can be made. While the Na B P O mixed glass former system exhibits a positive effect, new research has also discovered systems that show never before seen negative effects. This dual behavior of the effects is also observed in sulfide glasses. Here, B additions to a Na P S glass exponentially increase the ionic conductivity, whereas Ge additions to the same glass decrease its ionic conductivity. While progress has been made in understanding ionic conduction in solid electrolytes, significant knowledge gaps still exist. In undertaking this research, two doctoral graduate students and one undergraduate student will prepare and characterize new mixed glass former glasses that exhibit these opposite mixed glass former effects. Through this research, they will develop advanced laboratory-based research skills in materials science, glass research, and solid state electrochemistry. They will also develop computational skills and knowledge through an international collaboration with a leading glass theory and simulation research group in Germany where they will spend a 10-week summer research experience learning molecular dynamics and reverse Monte Carlo simulation techniques.

非技术描述太阳是一种巨大的未开发能源，具有昼夜循环的模式。因此，如果能解决安全、高成本和低效率的问题，就需要储能系统，而电池是正在考虑的很有前途的技术。考虑到所需的储能系统的规模，非常低的成本和丰富的地球资源的钠电池正在积极地研究。然而，今天的钠电池必须在300摄氏度下运行，因为电池隔板是一种固体电解液，具有低的Na+离子导电性，这导致这种电池效率低下、不安全和昂贵。由于这些原因，更好地了解Na+离子在固态中的运动是很重要的，这样才能开发出新的更好的导电固体电解质。在这个项目中，正在研究新的玻璃固体电解质，这种固体电解质可以非常便宜地制造出来，具有高的Na+离子电导率。具体地说，马丁的团队正在研究基于两种网络形成者(例如硅、硼或锗)的新三元玻璃，这两种网络形成者形成了高度交联的化学键排列。这些特殊的玻璃之所以被研究，是因为人们已经发现，在两种玻璃的某些组合中，Na+离子的导电性显著增加，而在其他组合中，Na+离子的运动显着减少。通过研究这两种不同的体系及其相反的行为，将有可能更多地了解Na+离子如何在固体中传导，并有助于开发基于更好的固体电解液的新型钠电池。技术上的DETAILSNa+离子掺杂到玻璃成型机中，在化学优化时可以具有非常高的导电性。例如，通过混合两种玻璃成形剂B和P，在恒定的Na+含量下，可以获得罕见的高离子导电性和改善的玻璃固体电解质的物理和电化学性质。这种基于地球富钠的优化混合玻璃前玻璃固体电解液可能是制造下一代更便宜、更安全、更高效的大型电网电池的候选材料。虽然Na B P O混合玻璃前驱体系统显示出积极的影响，但新的研究也发现了一些以前从未见过的负面影响。这种效应的双重行为也在硫化物玻璃中观察到。在Na P S玻璃中，B的添加使其离子电导率呈指数增加，而Ge的添加使其离子电导率降低。虽然在了解固体电解质中的离子传导方面已经取得了进展，但仍然存在着重大的知识空白。在进行这项研究时，两名博士研究生和一名本科生将准备并表征新的混合玻璃前玻璃，这种玻璃表现出这些相反的混合玻璃前玻璃效果。通过这项研究，他们将在材料科学、玻璃研究和固态电化学方面发展先进的实验室研究技能。他们还将通过与德国一家领先的玻璃理论和模拟研究小组的国际合作，发展计算技能和知识，在那里他们将花10周的夏季研究经验学习分子动力学和逆向蒙特卡罗模拟技术。