Fast-charging investigation on high-power and high-energy density pouch cells with 3D-thermal model development

In this paper, insight of thermal behavior of lithium-ion batteries under fast-charging profiles is investigated. Although battery thermal behavior has been studied by published models, the reported modeling addresses a specific application: fast-charging applications. Most papers in literature present the fast charging application from an electrical point-of-view. There, lacks a comprehensive electro-thermal model which can capture both the heat generation, voltage and current variation during the whole fast-charging process. In this study, two charging profiles that are commonly used for fast-charging applications are applied on two lithium-ion chemistries: lithium nickel manganese cobalt oxide (NMC) and lithium titanate (LTO). The first one is designed for high-energy density and the other made for high power applications. To enlarge the study scope, the batteries have been tested at three environmental temperatures: 25 degrees C, 10 degrees C and 45 degrees C. In addition, a three-dimensional thermal model has been developed within the frame of open source computational fluid dynamics (CFD) to analyze the thermal behavior of lithium-ion batteries (LiBs). Thermal evolutions of the cells during the profile are recorded to witness the temperature distribution and the validation of the model. The model has indeed well captured the evolution process of the cells from electrical and thermal point-of-views and achieved reasonably good agreement with the measurements. For example, LTO-based cells have shown an interesting behavior for which the battery was able to undergo a fast-charge at any tested temperature and the temperature still remained stable (a temperature rise of less than a 3 degrees C). These parametric studies demonstrate that the model methodology can be used to predict LiB temperature distribution under fast-charging profiles. (C) 2017 Elsevier Ltd. All rights reserved.