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.