LAUSR

Abstract Current distributions within large-format pouch cells or between cells in parallel circuits are of great interest for battery systems and have already been investigated in several studies. However, the approaches employed to both cases are often different. For instance, in parallel circuits, cell currents can be measured directly. On the other hand, these studies mostly consider cylindrical cells and active cooling is seldom regarded. For large-format cells, the current distribution can usually only be determined indirectly via inert temperature distributions or by means of elaborate models. This paper combines advantages of both approaches by imitating a large-format pouch cell segmented by a suitable parallel connection of smaller cells. The cell temperature can be individually controlled, with the help of Peltier elements, in order to investigate the influence of uneven heat distributions on the local cell currents. Most importantly, a linear relationship between the current distribution and the temperature gradient across the cell could be found, even for short current pulses. At lower temperatures this dependence becomes stronger. Moreover, it is shown that the findings from the parallel connection can be transferred to the large-size cell, since both behave almost identically at the terminals. This allows for a later modelling of such correlations without knowledge of extensive material parameters.