KlemA - classification of electromechanical aging on the operating condition of Lithium Ion Cells

The partners in this Project are:
Daimler AG, Volkswagen AG, Battery Center MEET of the University Münster, Institute EES of the TU München.

One approach to reduce the costs of automotive electrical energy storage systems is the “second use” of these systems, which will decrease the “total cost of ownership”. Therefore, it is essential to determine the aging condition of the lithium-ion batteries (LIB) to guarantee a safe and adequate application of the storage system in a “second use”.

Lithium Ion Batteries (LIB) show a slowly fading capacity up to a certain point when the capacity starts to drop significantly. It is not entirely understood which processes lead to this drop and how it can be predicted. Within this project, the classification of the aging condition is targeted. The mechanical behavior of LIB plays an important role but is often neglected. Due to ongoing aging processes the pressure within the cell rises. Combined with the outer mechanical restraint of the module or the pack the behavior of the LIB is affected. One main aim of the project is the analysis of the rising pressure and the influence on battery safety and lifetime. With this knowledge, construction and operating conditions for the first user (OEM) canbe deduced to permit a sustainable “second use” of the battery system.