Online thermal state estimation of high power lithium-ion battery

This paper concerns about thermal management issues of Li-ion battery for optimal and safe operation of the battery. For the thermal management, it is important to estimate implicit thermal states such as internal temperature and heat generation rate of the battery. This research presents an online thermal state estimation technique for a pouch-type Li-ion polymer battery. The thermal states are represented by a state space model based on an equivalent circuit model. A computational thermal dynamic analysis for Li-ion battery is used for identifying the model parameters. A state estimation technique is developed based on a state observer and energy balance equation. This technique is validated with a constant and dynamic current discharge experiment on a 5Ah pouch type Li-ion battery.