Thermal Management of LiFePO4 Battery Modules Using a Hybrid System Based on a U-Shaped Minichannel Cold Plate and Capric Acid PCM

Abstract

This study numerically investigates a hybrid battery thermal management system (BTMS) incorporating an aluminum mini-channel cold plate with a U-shaped configuration and capric acid phase change material (PCM) for a module of four 20 Ah LiFePO4 pouch cells. A three-dimensional CFD model was simulated in ANSYS Fluent and validated with experimental measurements, showing relative errors below 4% at low discharge rates and below 8% at high discharge rates (DR). The effects of discharge rate and coolant mass flow rate (ṁ w ) on battery temperature, temperature uniformity, pressure drop, and thermo-hydraulic performance were analyzed. The results indicate that increasing the discharge rate from 1C to 4C significantly leads to greater heat generation and thermal non-uniformity. At 4C, increasing ṁ w from 5×10 −4 to 1.75×10 −3 kg/s reduced the maximum battery temperature (T b,max ) from 34.65°C to 31.39°C and the maximum temperature difference (ΔT b,max ) from 3.74°C to 1.34°C. Considering both cooling enhancement and hydraulic losses, the optimal mass flow rate was found to be 1.25×10 −3 kg.s −1 . The proposed hybrid BTMS provides an effective solution for controlling battery temperature under severe operating conditions.