Influence of dry mixing and distribution of conductive additives in cathodes for lithium ion batteries
Influence of dry mixing and distribution of conductive additives in cathodes for lithium ion batteries
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DOI：
10.1016/j.jpowsour.2015.04.081
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发表时间：
2015-08-15
影响因子：
9.2
通讯作者：
Nirschl, Hermann
中科院分区：
文献类型：
--
作者：
Bauer, Werner;Noetzel, Dorit;Nirschl, Hermann
导电添加剂，如炭黑或石墨，是锂离子电池的重要组成部分，因为大多数电极材料的导电性有限。然而，仍然缺乏关于这些材料在电极内的优化分布的知识。采用干混法在Li（Ni 1/3 Mn 1/3Co 1/3）O-2（NMC）阴极颗粒表面沉积炭黑，制备导电涂层。它表明，这从理论上的角度来看，有利的分布不允许工作电极的制备，而不考虑粘合剂的作用。在将有机粘合剂添加到浆料中之后，聚合物在干燥期间沉积在碳壳的顶部上，并且抑制颗粒之间的导电接触。这可以通过与粘结剂相结合的一部分分布的碳颗粒来避免，所述粘结剂相提供穿过隔离有机材料的导电路径。结果表明，炭黑和石墨主要是完成这一任务，但这两种材料导致不同的加工行为和电极性能。(C)2015爱思唯尔B. V.保留所有权利。
Conductive additives, like carbon black or graphite, are essential components of lithium ion batteries due to the limited electrical conductivity of most electrode materials. However, there is still a lack of knowledge about the optimized distribution of these materials within the electrode. A dry mixing process is used in order to prepare a conductive coating by depositing carbon black on the surface of Li(Ni1/3Mn1/3Co1/3)O-2 (NMC) cathode particles. It is demonstrated that this from a theoretically point of view - favorable distribution does not allow the preparation of working electrodes without taking into account the role of the binder. After adding an organic binder to the slurry, the polymer deposits on top of the carbon shell during drying and inhibits the conductive contact between the particles. This can be avoided by a fraction of distributed carbon particles which are associated with the binder phase providing conductive paths through the isolating organic material. It is shown that carbon black and graphite are principally fulfilling this task, but both materials are leading to varying processing behavior and electrode properties. (C) 2015 Elsevier B.V. All rights reserved.