Thermal Management of Lithium-ion Battery Module With Forced Air and Conditioned Air Convection and Its Impact on Cell Aging

Lithium-ion cells are extensively used in Electric Vehicles (EVs) and renewable energy storage systems due to their high energy density and specific power. However, their thermal sensitivity necessitates effective thermal management to ensure safety, performance, and extended cycle life. This study presents a 2D thermal model developed using MATLAB, which employs the transient heat diffusion equation with internal heat generation to simulate thermal behavior of Lithium-ion cells. The model is validated against experimental data at 0.5C and 1C discharge rates and incorporates forced convection using air to regulate temperatures across discharge rates from 0.5C to 2C and coolant velocities from 1 to 5$m/s$. Results show a temperature rise from 32.6$^\circ$C (0.5C) to 52.8$^\circ$C (2C), with increasing coolant velocity lowering$T_{max}$but raising pumping power. Coolant with 1$m/s$and 25$^\circ$C kept$T_{max}$$< $40$^\circ$C and$\Delta T$$< $3$^\circ$C for 1C. The study is extended to a 10-cell battery module subjected to dynamic drive cycles and monthly ambient temperature variations. Further, analysis is performed to estimate capacity loss of battery module and impact of different cooling methods on aging. Capacity fade analysis reveals that under natural convection, the module achieves a cycle life of approximately 1000 cycles. In contrast, with conditioned air cooling, the cycle life exceeds 2200 cycles due to significantly lower average cell temperatures and reduced thermal stress. These insights support the development of efficient thermal management systems to enhance battery durability in real-world conditions.