Determination of Tortuosity Using Impedance Spectra Analysis of Symmetric Cell
Determination of Tortuosity Using Impedance Spectra Analysis of Symmetric Cell
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DOI：
10.1149/2.0331711jes
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发表时间：
2017-01-01
影响因子：
3.9
通讯作者：
Delacourt, Charles
中科院分区：
文献类型：
--
作者：
Malifarge, Simon;Delobel, Bruno;Delacourt, Charles
一种在不改变当前使用的正极和负极活性材料的情况下增加为运输应用开发的电池的自主性的方法是通过增加电极的活性材料负载（mg. cm（-2））来增加电池能量密度。更高负载的直接后果是跨电极孔隙率的质量传输相关问题的增加。因此，多孔电极结构的优化是强制性的，以促进锂离子进入整个电极体积。在这方面，孔隙弯曲度是一个关键参数，其确定并不那么简单。虽然层析成像技术和相应的分析是很有前途的方法，以获得精确的几何信息的多孔电极，他们很难被用作常规技术。在这项工作中，一个传输线模型分析的电化学阻抗图的对称细胞含有多孔电极在阻塞条件下，即没有任何电荷转移反应，提出了为了容易地推导出孔曲折。该方法适用于一组由各向异性颗粒组成的石墨电极。(C)作者（S）2017由ECS发布。All rights reserved.
An approach to increase the autonomy of batteries developed for transportation applications, without changing currently-used positive and negative active materials, is to increase the battery energy density by increasing the active material loading (mg.cm(-2)) of the electrodes. A direct consequence of a higher loading is the increase of mass transport-related issues across the electrode porosity. Therefore, the optimization of the porous electrode structure is mandatory to facilitate the access of lithium ions to the whole electrode volume. In this regard, pore tortuosity is a key parameter whose determination is not so straightforward. Although tomography techniques and corresponding analyses are promising methods to acquire precise geometrical information about porous electrode, they hardly can be used as a routine technique. In this work, a transmission-line-model analysis of the electrochemical impedance diagram of symmetric cells containing porous electrodes in blocking condition, i.e. without any charge transfer reaction, is proposed in order to readily derive pore tortuosity. The method is applied to a set of graphite electrodes composed of anisotropic particles. (C) The Author(s) 2017. Published by ECS. All rights reserved.