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Lithiation mechanisms of amorphous silicon electrodes in Li-ion batteries probed by in-operando neutron reflectometry

操作中中子反射测量法探讨锂离子电池非晶硅电极的锂化机制

基本信息

批准号：
266437955
负责人：
Professor Dr. Harald Schmidt
金额：
--
依托单位：
Institut für Metallurgie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/266437955?language=en
关键词：
Lithiation mechanisms amorphous silicon electrodes

项目摘要

Rechargeable lithium-ion batteries are widely used as energy storage devices and will be essential for future demands. An important step towards this direction is the implementation of negative electrode materials with a high specific capacity like silicon (4 Ah/g). Electrode processes during charging and discharging cycles play a key role for a fundamental understanding and an optimization of these batteries. Objective of the present proposal is the experimental determination of the mechanisms of electrochemically driven lithium incorporation/extraction (homogeneous/heterogeneous) in amorphous silicon electrodes by in-operando neutron reflectometry.Potentiostat controlled experiments on electrochemical cells with thin film and volume electrodes will be done during galvanostatic charging and additionally potentiostatic charging. Based on special modelling, the results will give information on the lithiation mechanism (homogenous Li incorporation, moving phase boundary etc.) as a function of current density, electrode potential and cycle number.In addition, ex-situ experiments with secondary ion mass spectrometry (SIMS), X-ray photo electron spectroscopy (XPS), and X-ray diffractometry (GIXRD) will be applied in order to obtain additional system parameters for electrode characterization and for a reliable modelling of reflectivity patterns.The experiments should contribute to a further development of neutron reflectometry as a promising method for in-operando characterization of battery systems.

可充电锂离子电池被广泛用作储能设备，对于未来的需求至关重要。朝这个方向迈出的重要一步是采用具有高比容量的负极材料，例如硅（4 Ah/g）。充电和放电循环期间的电极过程对于基本了解和优化这些电池起着关键作用。本提案的目的是通过操作中中子反射计实验确定非晶硅电极中电化学驱动的锂掺入/脱嵌（均质/异质）的机制。在恒电流充电和附加恒电位充电期间，将在具有薄膜和体积电极的电化学电池上进行恒电位仪控制实验。基于特殊模型，结果将提供有关锂化机制（均质锂掺入、移动相界等）与电流密度、电极电位和循环次数的关系的信息。此外，还将应用二次离子质谱（SIMS）、X射线光电子能谱（XPS）和X射线衍射（GIXRD）等非原位实验，以获得电极的其他系统参数这些实验应有助于中子反射测量法的进一步发展，作为电池系统操作中表征的一种有前途的方法。