Raw cycle data and CT images of the development of jelly roll deformation in 18650 lithium-ion batteries at low state of charge

In this dataset cycle test data as well as CT data used in publication The Development of Jelly Roll Deformation in 18650 Lithium-Ion Batteries at Low State of Charge (DOI: 10.1149/1945-7111/aba96d) are presented. In total 4 cells are shown with volume expansion data from strain gauge measurements in addition to voltage, current and temperature time series data. We performed CT measurements for each cell a before the test and after the test. In addition we measured one cell at several check-up procedures during the cell life. Based on the presented data, a theory is developed to determine the cause of the jelly roll deformation at low states of charge (0%–20% SOC). The diameter of the cell is increasing during ageing, which reflects the increase of the internal pressure. Continuously growing cover layers of chemical degradation explain the latter. It is concluded that for releasing internal pressure, the jelly roll starts to deform. This deformation accelerates the ageing processes by electrically isolating active material from the current collector and the formation of fresh SEI. In addition, the CT images are used to determine the time of the deformation. Conclusively, it is shown that the jelly roll deformation is driven by cyclic ageing. Due to the correlation of the mean diameter change and the capacity curve, the deformation of the jelly roll and thus the sudden cell death can be predicted by measuring the mean diameter change of the battery.