Abstract

The positive electrode of a Li-ion battery is made from active material, a binder and conductive material. In this work, the direct and interaction effects of these components on electrochemical performance of a Li-ion cell is studied using design of experiments. For this purpose, a two-level full factorial design was used and interactions were analyzed using analysis of variance. The content of carbon black and graphite as conductive materials and polyvinylidene difluoride as binder are considered as input parameters. Theactive material is NCM622 in the current work. Initial discharge capacity and Warburg coefficient obtained from impedance spectroscopy are output responses. Eleven experiments along with the central points were conducted to determine the relationship between process parameters and the output responses. This information is needed to optimize the output. It was observed that all three parameters are significant. In low carbon black and graphite content, the binder has a negative effect on both parameters, but in high levels of carbon black content it has a positive effect due to the better connectivity of carbon particles with each other. The results show that interaction of carbon black-binder and carbon black-graphite are also significant. Mathematical models were presented in order to optimize the parameters.

Graphic Abstract

中文翻译：

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通过锂离子电池实验设计优化正极材料成分

摘要

锂离子电池的正极由活性材料，粘合剂和导电材料制成。在这项工作中，使用实验设计研究了这些成分对锂离子电池电化学性能的直接作用和相互作用。为此，使用了两级全因子设计，并使用方差分析对相互作用进行了分析。作为输入材料的炭黑和石墨的含量以及作为粘合剂的聚偏二氟乙烯的含量被认为是输入参数。当前工作中的活性材料为NCM622。从阻抗谱获得的初始放电容量和Warburg系数是输出响应。进行了11个实验以及中心点，以确定过程参数与输出响应之间的关系。需要此信息来优化输出。观察到所有三个参数都是重要的。在低的炭黑和石墨含量下，粘合剂对两个参数均具有负面影响，但在高的炭黑含量下，由于碳颗粒彼此之间具有更好的连通性，因此具有积极的效果。结果表明，炭黑粘合剂与炭黑石墨的相互作用也很显着。提出了数学模型以优化参数。结果表明，炭黑粘合剂与炭黑石墨的相互作用也很显着。提出了数学模型以优化参数。结果表明，炭黑粘合剂与炭黑石墨的相互作用也很显着。提出了数学模型以优化参数。

图形摘要