Battery Heterogeneity Challenge: From Single to Multiple Cell System Modelling

Abstract

Significant efforts have been dedicated to optimising the performance of battery systems by improving energy management and battery sizing strategies. Recent advancements have shifted their focus on model-based optimisations and machine learning-based techniques. To assess the effectiveness of these strategies, key indicators, such as battery aging-rate and available energy/capacity, have been widely used. Nevertheless, a critical factor – cell-to-cell heterogeneity, which has been extensively documented in the literature – is often overlooked, casting doubt on the assessment of many advances. In response to this gap, an electro-thermal simulation framework has been developed. This simulation tool allows full customisation of the system architecture. Results highlight the variability that can emerge when analysing systems of different sizes and drawing on the heterogeneity observed at individual cell level parameter distributions. Findings also enable a comparison between single-cell simulations—commonly used in the literature—and full system-level simulations, including the additional computational complexity the latter entails. Ultimately, it is up to each researcher to determine whether such variability is a critical factor in the evaluation of their energy management approach and battery sizing strategy.