Electrothermal modeling and characterization of high capacity lithium-ion battery systems for mobile and stationary applications

In mobile and stationary battery systems, lifetime expectancy is a key parameter for the calculation of monetary effectiveness. It significantly affects return on investment and therefore is a key parameter for the market breakthrough of the desired battery application. Battery life is influenced by two different factors, namely electrical utilization and environmental conditions. As higher temperatures lead to a faster deterioration of the lithium-ion battery, smart thermal design can not only increase battery lifetime, but also reduce cooling costs and improve overall efficiency. It is therefore essential to establish an effective thermal design through perfoming electrothermal modeling and characterization of the battery cell, battery module and fully assembled battery pack. In this paper, the motivation for electrothermal modeling of lithium-ion battery cells and modules is introduced and design challenges are identified for applications in mobile and stationary bat tery systems. An electrothermal model of batteries with appropriate cell chemistry for mobile and stationary applications is developed with focus on further implementation in thermal simulation of battery modules and packs. The parameterization process of the presented models is shown and a model of battery cells with derived parameters is presented. Finally, the electrothermal model is verified experimentally.