Modeling and validation on the respective contributions of positive and negative tabs for 18650 cell

• Published in: Journal of energy storage 2018-12, Vol.20, p.439-450
• Main Authors: An, Fu-qiang, Zhou, Wei-nan, Li, Ping
• Format: Article
• Language: English
• Subjects: Electrochemical-thermal model; Experimental validation; Lithium-ion cell; Tab layout
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2018.09.014

•A two-dimensional radial electrochemical model is used for studying the 18650 tab layouts.•The optimization of the tab layouts is based on the mainstream design of commercial 18650.•Large ohm impedance on the negative electrode damages the performance of the mainstream design.•The modeling results are in good qualitative agreement with experimental data. The layout of the current collecting tabs is an important design parameter due to their ability to affect current distribution and cell ohm resistance for 18650-type cell. In this work, a simplified 2D radial winding model of 18650 has been established to study the tabs’ layout designs based on the mainstream design where one positive tab is placed in the middle and one negative tab is placed at the outer end. Different layouts of positive and negative tabs have been investigated separately to seek the change of cells’ internal and extrinsic characteristics, so as to find a more applicable tab design to improve the high rate performance of 18650. The modeling results suggest that arranging multi-tabs on the negative electrode has better performance than the positive electrode with multi-tabs based on the mainstream tab design. More specifically, two negative tabs at the opposite ends with one positive tab at the center provide a significant benefit while further increases in the number of either positive or negative tabs contribute to a marginal improvement in voltage and temperature rise. Meanwhile, these modeling results have been well-validated by test results.