| dc.description.abstract | This master’s thesis investigates the impact of battery cell orientation on cycling and aging behaviour, focusing exclusively on Samsung 35E - 18650 cells. Previous research has suggested a recovery and gravity effect in 18650 cells. The primary objectives of this study were to determine if differences exist between vertical and horizontal orientations, to examine the recovery of aged cells post-storage, and to analyse lithium plating and electrode conditions following cell disassembly. Additionally, the study included an investigation of the conducting salt concentration gradient.
The results indicate that vertically oriented cells exhibit a more significant capacity loss compared to horizontally oriented cells. Furthermore, cells cycled within a low Depth of Discharge (DoD) window experience more damage than those cycled within a full 100% DoD window. The recovery effect appears to depend on the cell's state of health; no recovery was detected in cells cycled to End of Life, whereas cells cycled for one hundred equivalent full cycles showed a recovery effect after a four-week rest period. Lithium plating was observed in all cells cycled to End of Life, correlating with the cycling data. Interestingly, cells cycled for one hundred full cycles and opened immediately showed no lithium plating, whereas cells with the same cycling conditions but a four-week rest period exhibited lithium plating. | |