Thermal Behavior of Small Lithium-Ion Secondary Cell during Rapid Charge and Discharge Cycles

Abstract

In the present study, in order to make the thermal simulation model for large lithium-ion secondary batteries, overpotential resistance, enthropy change, cell heat capacity, and heat transfer coefficient for the commerial cell have been measured. Using these measured data, the thermal simulation model calculates the cell temperature during rapid charge and discharge cycles, which calculated results have been compared with the measured temperature to confirm the validity of this model. The one-dimensional thermal simulation model gives the cell temperature profile, which shows the maximum temperature difference between center and surface of 1.6°C during 3C discharge. So we assumed that the cell temperature distribution is uniform during rapid charge and discharge cycles. The thermal simulation model with a representative cell temperature was made in using the measured data described before. The calculated temperature by this model agrees well with the cell temperature measured by a thermocouple. Therefore we can confirm the validity of our thermal simulation model to predict the cell temperature during rapid charge and discharge cycles.