Presentation by Frank Cord Lohmann, Project Manager at Altair.
The steady shift from conventional (combustion) powertrains to hybrid or full electric powertrains goes hand in hand with a steady increase in traction battery size, power and capacity. While passive cooling (air cooling) might have been sufficient for smaller HEV and BEV batteries, current battery setups for full electric vehicles very much require active cooling to ensure battery performance, durability and operational safety. Therefore, the design of battery cooling systems is a critical aspect of overall traction battery design.
As a rule of thumb, current lithium-ion batteries need to be kept in a thermal operation window between 10°C and 40°C. Operational temperatures above 40°C will sharply decrease battery performance, and if allowed to stay above 40°C for a significant amount of time will permanently degrade battery lifetime and safety. Therefore, battery cooling must be designed to ensure operations within this window for all climatic and operational conditions. Simulation of the battery and battery cooling system provides valuable insights about battery performance and heat build-up in the early stages of battery cooling system design, at a time when physical prototypes do not yet exist and testing is thus not possible.
In this presentation, we will walk through the steps of early cooling plate design, using simulation to optimise pressure drop, coolant flow rates and general cooling performance as well as making first predictions on cell temperatures for different operating conditions and doing preliminary operational profile runs in preparation for a full vehicle simulation. We will also talk about model interfaces to other simulations tools and simulation disciplines, and how the model of cooling plate and battery can be expanded from a thermal model to a full multiphysics model.