The key challenge in developing a physico-chemical model is the model parameterization. The paper presents a strategic model parameterization procedure, parameter values, and a developed model that allows simulating electrochemical and thermal behavior of a commercial lithium-ion battery with high accuracy. Steps taken are the analysis of geometry details by opening a battery cell under argon atmosphere, building upon reference data of similar material compositions, incorporating cell balancing by a quasi-open-circuit-voltage experiment, and adapting the battery models reaction kinetics behavior by comparing experiment and simulation of an electrochemical impedance spectroscopy and hybrid pulse power characterization. The electrochemical-thermal coupled model is established based on COMSOL Multiphysics® platform (Stockholm, Sweden) and validated via experimental methods. The parameterized model was adopted to analyze the heat dissipation sources based on the internal states of the battery at different operation modes. Simulation in the field of thermal management for lithium-ion batteries highly depends on state of charge-related thermal issues of the incorporated cell composition. The electrode balancing is an essential step to be performed in order to address the internal battery states realistically. The individual contribution of the cell components heat dissipation has significant influence on the temperature distribution pattern based on the kinetic and thermodynamic properties.

To draw reliable conclusions about the thermal characteristic of or a preferential cooling strategy for a lithium–ion battery, the correct set of thermal input parameters and a detailed battery layout is crucial. In our previous work, an electrochemical model for a commercially-available, 40 Ah prismatic lithium–ion battery was validated under heuristic temperature dependence. In this work the validated electrochemical model is coupled to a spatially resolved, three dimensional (3D), thermal model of the same battery to evaluate the thermal characteristics, i.e., thermal barriers and preferential heat rejection patterns, within common environment layouts. We discuss to which extent the knowledge of the batteries’ interior layout can be constructively used for the design of an exterior battery thermal management. It is found from the study results that: (1) Increasing the current rate without considering an increased heat removal flux at natural convection at higher temperatures will lead to increased model deviations; (2) Centralized fan air-cooling within a climate chamber in a multi cell test arrangement can lead to significantly different thermal characteristics at each battery cell; (3) Increasing the interfacial surface area, at which preferential battery interior and exterior heat rejection match, can significantly lower the temperature rise and inhomogeneity within the electrode stack and increase the batteries’ lifespan.

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For several years lithium-ion batteries have been commercially used in portable devices such as camcorders, laptop computers and cell phones. Battery lifetime plays only a minor role in such applications due to rapid product innovation and strong competition. However, the increasing demand for lithium-ion batteries for automotive traction applications requires drastic increase in battery life-time and safety.[1] The majority of the existing life-time and performance prognoses are based on accelerated aging tests at elevated temperatures such as 40 °C, since the temperature plays a crucial role on the battery performance, safety and life-time. However automotive lithium-ion cells must endure multiple production processes during the fabrication of a high-end traction battery system, such as contact welding, where the cells are exposed to elevated temperatures for a short period of time.[2] Up to date there is little information on the temperature propagation within the cell during the short-term thermal stress and also the influence of such short period thermal stress on the cell performance and cyclic ability. For a better understanding of the temperature propagation in the cell, a simulation model based on the thermal material characteristics of a prismatic Li-NiMnCoO2 cell was created in COMSOL Multiphysics®. The thermal characteristics of the battery components are experimentally determined using Laser Flash Analysis (LFA) and Differential Scanning Calorimetry (DSC). In order to validate the modeling approach in this work, we built an experimental setup to measure the temperature propagation within a dummy cell. This dummy cell includes a carbonate solution as electrolyte, yet without a lithium salt. After validating the model is used to describe the temperature propagation after a short-term temperature stress on automotive lithium-ion cells. Furthermore, it’s possible to predict the temperature propagation in the cell with this simulation model, after the short-term stress on different positions on the cell casing surface and at different SOC’s. [1] J. Vetter, P. Novák, M.R. Wagner, C. Veit, K.-C. Möller, J.O. Besenhard,M. Winter, M. Wohlfahrt-Mehrens, C. Vogler, A. Hammouche; Ageing mechanisms in lithium-ion batteries. J. Power Sources 147 (2005) 269–281 [2] M. Yoshio, R.J. Brodd, A. Kozawa; Lithium-Ion Batteries, Science and Technologies; Springer (2009)

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