Question: How do we have to build and regulate the cooling of the lithium-ion battery for our vehicle to maximize service life?
Our client wanted to have a component model in Simulink, which he could pass on to his colleagues from the system simulation. The component model should consider all factors influencing the lithium-ion battery and calculate the temperature of the cell’s three-dimensionally and transiently. The decisive factor was that the model had to be compiled so it would not be changed.
Project Manager, battery manufacturer.
The lifetime of lithium-ion batteries depends strongly on the temperature. If the cell is too cold, it cannot be charged well. If it becomes too warm, the service life will be reduced.
For our clients, it was important to map out the physics of the cell accurately to represent the temperature in driving cycles as a function of the ambient temperature etc. He wanted a three-dimensional, non-stationary model of the energy budget to optimize the design. He wanted to pass this model to his colleagues from the System simulation team in compiled form so they could also make calculations.
In this project, it should be verified and demonstrated by the prototype which possibilities of optimization exist to set up a series of development projects.
We have built a model of the lithium-ion battery in Simulink for our clients. This consists of approximately 500 partial differential equations that describe the energy balance of the battery system. The main effects are the heat source terms due to the chemical reaction during loading and unloading, the heat input from the outside, the convection cooling through the coolant, and the anisotropic heat conduction in and between the cells.
The model is real-time capable and has five input parameters as F (t): Power requirement, mass flow coolant, temperature coolant, input pressure coolant, ambient temperature. The output parameters are the outlet temperature of the coolant, the output pressure of the coolant, and the actual suppliable current (which can be less than the requested one).
Our client had a single, compiled block and full access to all formulas.