Thermal Management of Large-Format Prismatic Lithium-Ion Battery in PHEV Application

Abstract

Thermal effects are linked to all main barriers to the widespread commercialization of lithium-ion battery powered vehicles. This paper presents a coupled 2D electrochemical – 3D thermal model of a large-format prismatic lithium-ion battery, including a thermal management system with a heat sink connected to the surface opposite the terminals, undergoing the dynamic current behavior of a plug-in hybrid electric (PHEV) vehicle using a load cycle with a maximum current of 8 C, validated using potential and temperature data. The model fits the data well, with small deviations at the most demanding parts of the cycle. The maximum temperature increase and temperature difference of the jellyroll is found to be 9.7°C and 3.6°C, respectively. The electrolyte is found to limit the performance during the high-current pulses, as the concentration reaches extreme values, leading to a very uneven current distribution. Two other thermal management strategies, short side and long side surfaces cooling, are evaluated but are found to have only minor effects on the temperature of the jellyroll, with maximum jellyroll temperatures increases of 9.4°C and 8.1°C, respectively, and maximum temperature differences of 3.7°C and 5.0°C, respectively.

Thermal Modelling of a Prismatic Lithium-Ion Cell in a Battery Electric Vehicle Environment: Influences of the Experimental Validation Setup

“…Geometric dimensions and electrical and thermal behaviour are determined experimentally and subsequently used for the parametrization of the model. Furthermore, physical properties are taken from [7,23]. Important for the thermal behaviour of the cell are the conditions of use, especially the cooling conditions.…”

“…In order to answer the scientific issue of thermal battery behaviour, researchers develop different electro-(chemical)-thermal coupled simulation models [4][5][6][7][8][9][10][11][12]. Most of them are based on the general energy balance for lithium-ion based systems [13] in its detailed or simplified form.…”

“…In lithium-ion batteries, non-linear physico-chemical processes occur on different length scales from nanometre to millimetre. To face this challenge, model-based thermal investigations of battery cells are performed and reported in the literature in two fundamentally different ways: They use independent thermal models on the one hand with defined heat generation and on the other hand models with electrical or electrochemical-thermal coupling [6][7][8][10][11][12]14].…”

“…The latter approach, electrically and thermally coupled behaviour, is described in the literature with different model approaches. Researchers use either the pseudo-two-dimensional modelling approach [7,8,12] based on the work of Newman et al [15,16], equivalent circuit models (ECM) [9], and empirical models [11]. The thermal model can i.e., be executed as a point model [6] or can also be resolved three-dimensionally [7].…”

“…In this work, we focus on the automotive use case of prismatic cells in module architecture on a cooling plate-like in [6,7]. Lundgren et al [7] suggest a detailed 3D electrochemical-thermal model with experimental validation of a prismatic cell. However, they do not consider the influences of the experiment such as wiring to the battery cycling machine or the cell's environment.…”