Experimental Thermal Analysis of Prismatic Lithium Iron Phosphate (LiFePO4) Battery

Characterizing the thermal parameters of a lithium-ion battery is an important step for estimating the temperature distribution of battery cell modules. In this study, an experimental method based on distance-dependent heat transfer analysis of the battery pack has been developed to simultaneously determine the thermal conductivity of the battery cell and the specific heat of the battery pack. Prismatic lithium iron phosphate cells are used in this experimental test. The time-dependent results were measured by measuring the temperature change of the cell surface. It is observed that the thermal parameters of the cell increase linearly with increasing operating temperature. Moreover, while the operating temperature has a more significant effect on the specific heat of the cell than the thermal conductivity, the effect of its state according to the C ratios used in charging and discharging has a maximum effect on these two parameters. The current method shows an effective and practical way to simultaneously determine the thermal conductivity of the cell and temperature changes.