Internal resistance mapping preparation to optimize electrode thickness and density using symmetric cell for high-performance lithium-ion batteries and capacitors
Internal resistance mapping preparation to optimize electrode thickness and density using symmetric cell for high-performance lithium-ion batteries and capacitors
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DOI：
10.1016/j.jpowsour.2018.05.083
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发表时间：
2018-08-31
影响因子：
9.2
通讯作者：
Naoi, Katsuhiko
中科院分区：
文献类型：
--
作者：
Kisu, Kazuaki;Aoyagi, Shintaro;Naoi, Katsuhiko
表征和优化电极内阻的方法对于在锂离子电池中同时实现高能量密度和高功率密度的目标至关重要。在这项研究中，我们提出并确认了一种基于内阻图的电极设计优化方法的有效性，内阻图是一种用于最小化电极电阻的可视化工具。通过识别电极电阻电荷转移电阻、离子电阻和接触电阻的三个主要组成部分，并阐明每个组成部分对电极密度和厚度的依赖性，来构建地图。我们制作各种密度和厚度的电极片，并进行电极阻抗谱（EIS）测量，以测量内部电阻对密度和厚度的依赖性，我们通过经验公式将其特征纳入我们的内部电阻图。使用我们的地图，我们预测，每单位面积的镍钴锰（NCM）电极的电阻达到其最小值，厚度为70 μ m，密度为2.9克cm（-3）。然后，我们进一步使用该地图来预测不同密度的NCM电极的IR降的变化，获得与实验测量非常一致的结果。
Methods for characterizing and optimizing the internal resistance of electrodes are crucial for achieving the simultaneous goals of high energy density and high power density in lithium-ion batteries. In this study we proposeand confirm the efficacy ofa method for electrode design optimization based on the construction of an internal resistance map, a visualization tool for minimizing electrode resistance. The construction of the map proceeds by identifying the three primary components of the electrode resistancecharge-transfer resistance, ionic resistance, and contact resistanceand elucidating the dependence of each component on electrode density and thickness. We fabricate electrode sheets of various densities and thicknesses and conduct electrode impedance spectroscopy (EIS) measurements to measure the dependence of internal resistance on density and thickness, which we characterize via empirical formulas incorporated into our internal resistance map. Using our map, we predict that the resistance per unit area of a nickel-cobalt- manganese (NCM) electrode attains its minimum value at thickness 70 mu m and density 2.9 g cm(-3). We then further use the map to predict variations in IR drop for NCM electrodes of different densities, obtaining results in excellent agreement with experimental measurements.