Temperature Distribution on Lithium-ion Polymer Battery: From 12V Module to 48V Pack

The performance, safety, and lifetime of lithium-ion battery are significantly affected by its operating temperature, which is the result of the ambient temperature combined with the heat generation from the battery. Understanding the heat generation characteristics and temperature distribution of the lithium-ion batteries is important to design the effective thermal management system (TMS). In this paper, a battery module consists of four series-connected lithium polymer cells is constructed. The surface temperature of the cells in the module is measured by eight thermocouples during discharging tests under different ambient temperatures. The thermal model of the battery module is created in ANSYS Fluent and the simulated temperature distribution data is collected. The simulated data is validated by the experimental data with acceptable discrepancy. A simplified 48V battery pack thermal model is then created in ANSYS Fluent using the validated module model as a base unit. The simulated temperature distributions across the 48V battery pack are also presented. The proposed battery thermal model provides a design guideline to thermal management system for battery module and pack.