Investigating the temperature behavior of battery cells has become a critical aspect of modern battery management systems. Recent developments in this field show that the temperature of a cell during charging varies based on the applied voltage. With an in-operando measurement method, this behaviour can be utilized to determine the State of Health (SoH). This approach presents new opportunities for quickly determining the degree of aging in vehicle battery cells.
In this study, similar cells were aged under either calendric or cyclic aging conditions. The resulting data was analyzed using the Differential Thermal Voltammetry (DTV) technique, to obtain information about the primary degradation mechanisms. These findings were then compared to the results from a Pseudo-Two-Dimensional (P2D) model, which provided a deeper understanding of the underlying electrochemical processes. Finally, complementary post-mortem analysis was conducted to enable a detailed evaluation of the different degradation modes and their origins.
The goal of this work is to develop lookup tables for the cells within our portfolio. This will lead to an in-depth understanding of the cells, their behaviors, and the predominant degradation modes. Ultimately, it enables SoH determination based on charging cycles, offering a streamlined method for assessing the aging stage of batteries used in commercial vehicles.