Infrared Diagnostics of a Li-Polymer Battery for the Estimation of the Surface Temperature Distribution and the Heat Transfer Parameters

Growing number of electric vehicles (EV) and hybrid electric vehicles (HEV) in the present market depicts the rapid growing demand for energy storage systems. The battery's main peculiarities must be the power density and reliability over time. The temperature strongly affects battery performance for low and high intensity. In particular,the management of the heat generated by the battery itself is one of the main aspects to handle to preserve the performance over time. The objective of this paper is to compare the surface temperature of the lithium-ion polymer battery at different discharging rates by infrared thermography. Thermal imaging is performed to detect the battery surface temperature distribution,focusing on its variation over time and the local inhomogeneity. Temperature measurements are then used to estimate the contributions of the different heat transfer mechanisms for the dissipation of the heat generated by the battery. A reverse-logic approach is used to derive the thermal parameters of the battery from the experimental data and power balance equations.