Performance comparisons and resistance modeling for multi-segment electrode designs of power-oriented lithium-ion batteries

This study investigates the influence of tab position and quantity as well as multi-segment electrodes in cell design for the performance of an 18650 power-oriented lithium-ion cell. The resistances of cells with traditional and center-tab designs are simulated by a simplified model. It shows that tab position significantly influences the cell resistance even when other components in the cell are fixed. The performances of both center-tab and traditional designs are compared by the cell direct-current resistance (DCR), body temperature, and 15 A cycling test to demonstrate the impact of cell design. The multi-tab design also shows better performance than the single-tab design for power cells; however there are diminishing returns for cells with three or more tabs as the additional tabs do not significantly reduce the cell resistance. The two-tab design is concluded to be the best choice for an 18650 power cell considering the process ability and overall high-rate performance. The difference in the waste power between the center-tab and the traditional designs, which is transformed into heat, is the main reason for the poor high-rate cycling performance as expected. Such modeling provides a quick design reference for a power cell with new size to get the most suitable electrode design. (C) 2010 Elsevier Ltd. All rights reserved.