Interface phenomena in ionic systems: a surface science approach

离子系统中的界面现象：表面科学方法

基本信息

批准号：
258032533
负责人：
Professor Dr. Karsten Albe
金额：
--
依托单位：
Fachgebiet Oberflächenforschung
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2014
资助国家：
德国
起止时间：
2013-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/258032533?language=en
关键词：
Interface phenomena ionic systems surface

项目摘要

Electrochemical devices with ionic electrodes are of central importance to our future energy economy. Interfaces in such electrochemical devices play a key role for their performance, but are not understood on a fundamental level. In this project, we aim to improve the fundamental understanding of practical interfaces. To this end, we investigate interfaces in Li-ion batteries.More specifically, this proposal aims to investigate the structure and reactivity of heterogeneous interfaces inside Li-ion battery composite cathodes and their influence on lithium ion and electron transport. By combining experimental and computational studies our goal is to better understand battery performance as well as failure modes and subsequently elaborate a rational design of the interfaces. Our proposal therefore addresses key issues for the future design of advanced battery devices, as well as electrochemical devices in general.Our approach is to characterize well defined hetero-interfaces by surface science methods and combine the results with theoretical calculations. Interfaces are prepared step-by-step by condensation from the gas phase, and analyzed by photoemission after each step. This methodology has been shown to yield unique insights about interface formation and properties, such as energy level alignment, presence of dipole- and space charge layers as well as ion- and electron transfer. The focus of the work is on electrode/electrolyte interfaces.For the experimental part of the work, we apply our UHV-cluster system at Darmstadt, dedicated to battery research, and our UHV-based solid-liquid analysis system at Bessy II in Berlin. We prepare specific interfaces by deposition of hetero film sequences, using physical vapor deposition methods, or by adsorption of volatile electrolyte species. Analysis by photoemission is supported by other surface science techniques, such as HREELS and HRTEM, as well as standard electrochemical and electrical measurements.Due to the fundamental nature of the proposal, work is conducted on well known materials. Interfaces of cathode material both with electrolyte (liquid as well as solid) and current collector materials are addressed. Specifically, we will prepare LixCoO2 thin films and investigate the interface formation as function of lithium content. The solid electrolyte is nitrogen-substituted phosphate glass (LiPON), the standard liquid electrolyte species the solvent diethyl carbonate (DEC).

具有离子电极的电化学设备对我们未来的能源经济至关重要。这种电化学设备中的接口对其性能起着关键作用，但在基本水平上并不理解。在这个项目中，我们旨在提高对实际界面的基本理解。为此，我们研究了锂离子电池中的界面。更具体地说，该提案旨在研究锂离子电池复合材料阴极内异质界面的结构和反应性及其对锂离子和电子传输的影响。通过结合实验和计算研究，我们的目标是更好地了解电池性能以及故障模式，然后详细阐述界面的合理设计。因此，我们的建议解决了先进电池设备的未来设计的关键问题，以及一般的电化学设备。我们的方法是通过表面科学方法来表征定义明确的异方面，并将结果与理论计算相结合。通过与气相的凝结逐步制备接口，并在每个步骤后通过光发射进行分析。该方法已被证明可以产生有关界面形成和特性的独特见解，例如能级对准，偶极子和空间电荷层以及离子和电子传递。工作的重点是电极/电解质接口。对于工作的实验部分，我们在Darmstadt应用了UHV群集系统，专用于电池研究，以及我们在柏林Bessy II的基于UHV的固体液体分析系统。我们使用物理蒸气沉积方法或通过吸附挥发性电解质物种来制备特定界面。通过光发射的分析得到了其他表面科学技术的支持，例如HREEL和HRTEM，以及标准的电化学和电气测量。有关该提案的基本性质，对知名材料进行了工作。处理了用电解质（液体和固体）和电流收集器材料的阴极材料的接口。具体而言，我们将准备LixCoo2薄膜，并研究界面形成作为锂含量的功能。固体电解质是氮取代的磷酸盐玻璃（Lipon），标准液体电解质物种溶剂二乙酯（DEC）。