Experimental Measurements of Thermal Characteristics of LiFePO ₄ Battery

A major challenge in the development of the next generation electric and hybrid electric vehicle (EV and HEV) technology is the control and management of heat generation and operating temperatures. Vehicle performance, reliability and ultimately consumer market adoption are integrally dependent on successful battery thermal management designs. In addition to this, crucial to thermal modeling is accurate thermo-physical property input. Therefore, to design a thermal management system and for thermal modeling, a designer must study the thermal characteristics of batteries. This work presents a purely experimental thermal characterization of thermo-physical properties of a lithium-ion battery utilizing a promising electrode material, LiFePO₄, in a prismatic pouch configuration. In this research, the thermal resistance and corresponding thermal conductivity of prismatic battery materials is evaluated. The experiment was designed to measure the thermal conductivity of both the individual electrode layers, and the overall thermal resistance of the sealed prismatic structure. For this experiment, the first step was battery dissection, the second step was sample preparation and the third step was the measurement of thermal resistance. Thermal resistance measurements were made using specially constructed battery samples. The thru-plane thermal conductivity of LiFePO₄ positive electrode and negative electrode materials was found to be 1.79 ± 0.18 W/m°C and 1.17 ± 0.12 W/m°C, respectively.