Enhanced thermal management system for Li-ion batteries using phase change material and liquid cooling under realistic driving cycles

Abstract

Designing effective thermal management for electric vehicle batteries is crucial for ensuring safety, reliability, while minimizing weight and operational costs. This study examines a hybrid battery thermal management system (HBTMS), integrating liquid-cooled plates with phase change material (PCM). We evaluate both continuous (CC) and intermittent cooling (IC) strategies across four realistic drive cycles and two rapid discharge-charge cycles, with configurations including natural convection, standalone PCM, serpentine cold plate (SCP) without PCM, and hybrid cold plates in serpentine and zig-zag patterns (ZCP) with PCM. The hybrid ZCP enhances thermal performance over traditional designs by increasing coolant turbulence and PCM mixing, reducing system weight by 52.9 % due to the lower density of PCM. Using IC, which adjusts coolant flow based on PCM melt fraction, hybrid ZCP decreases pumping power by up to 83.9 % and reduces coolant flow duration to 13.9 % of total cycle time. Higher coolant velocities lower battery temperatures but increase pumping power, whereas lower inlet temperatures accelerate cooling and PCM solidification. While CC offers better thermal regulation, IC markedly reduces energy consumption while maintaining adequate thermal performance, demonstrating the hybrid ZCP's efficacy.