Incremental thermo-electric CFD modeling of a high-energy Lithium-Titanate Oxide battery cell in different temperatures: A comparative study

Abstract

In this article, we address the following question: Which of the many CFD models should a designer use for battery thermal analysis? We present a comparative study of four thermo-electric CFD models for a novel high-energy Lithium-Titanate Oxide (LTO) cell to be used in an electric rallycross car prototype. In contrast to many related articles, the data required and the process of parameter identification are described in detail for each of the models, and we also address different operating temperatures. Moreover, the models’ relative performance in predicting cell behavior in constant current and varying current discharge situations is addressed by comparisons to cycling measurements and thermal camera imaging. The one key insight of this analysis is that, for purely thermal considerations, the accuracy of a simple constant internal resistance based heat generation model is remarkably close to a dynamic equivalent circuit model, which is considerably more tedious to identify. A limitation of this work is that we focus only on discharging, but the methods and models can also be used in charging situations in the future.