Lightweight thermal management strategy for Li-ion pouch cells using localised cold plate and graphite sheet

Thermal management is critical to ensure the performance, safety, and lifespan of Li-ion cells. The best cooling system for electric vehicles should have balance between thermal performance and overall weight. This study presents a liquid cooling solution through the multi-objective optimization of T-shaped cold plate combined with graphite sheet. Optimization is performed using combined strategy using latin hypercube sampling, artificial neural network and non-dominated sorting genetic algorithm on the 3S1P module by numerical simulations. The objective is to minimize the maximum temperature, temperature non-uniformity of the module, and cold plate weight. The best design, identified, features a horizontal height of 25.76 mm, a vertical width of 34.78 mm, and a channel depth of 3.77 mm. Experimental investigation of the optimized cold plate along with graphite sheets on the single cell reduces maximum temperature by 3.3 to 4.8 °C and temperature non-uniformity by 1.8 to 2.7 °C across various flow rates while reducing cold plate weight by 12.3% compared to the baseline design. The integrated optimized cooling system is numerically scaled to module level and tested under a realistic drive cycle, demonstrating a 2 °C reduction in peak temperature and a 2.1 °C reduction in non-uniformity at coolant temperature of 40 °C. This configuration achieves baseline thermal performance with a 71.25% reduction in mass flow rate. The final design is tested using graphene nanofluid with ethylene glycol (30%) and water (70%) as base fluid, showing thermal performance comparable to water at 1% mass fraction. The proposed design offers a lightweight and efficient solution for next-generation battery cooling systems in electric vehicles.