3-DIMENSIONAL THERMAL MODELING OF LITHIUM-POLYMER BATTERIES UNDER GALVANOSTATIC DISCHARGE AND DYNAMIC POWER PROFILE

A three-dimensional model is developed to simulate and compare heat ge neration and transport within a lithium polymer electrolyte battery un der galvanostatic discharges and a dynamic power profile [the Simplifi ed Federal Urban Driving Schedule (SFUDS)]. Emphasis is placed on the maintenance of the operational temperature and temperature uniformity within a battery by designing a suitable thermal management system. Th e results indicate that the anisotropic thermal conductivity within th e battery is an important factor influencing thermal performance and s hould be taken into consideration in battery design. On the one hand, because of the low effective thermal conductivity across a laminated c ell stack, steep temperature distributions may be caused if cooling ch annels or electric heaters are placed at the two ends of a cell stack. On the other hand, the relatively large average thermal conductivity along the width and height directions allows more efficient heat remov al or addition, and thus facilitates the maintenance of uniform operat ing temperature. Under the SFUDS power profile, the time-averaged heat generation rate is low, and therefore a high-performance insulation m aterial is required to maintain the operating temperature. The thermal model has been applied to study the effectiveness of different arrang ements of cooling channels and electric heaters and to select suitable heating intensities and insulating materials.