Coordinated thermal management of prismatic battery packs using cascaded PCM–liquid cooling coupling

An integrated prismatic battery thermal management system featuring a cold plate with cascaded phase change materials (PCMs) and embedded liquid cooling channels is proposed. A state-feedback control strategy activates intermittent liquid cooling based on real-time PCM liquid fraction, enabling periodic latent heat recovery and synergistic transient buffering with sustained heat dissipation. The effects of thermal management configuration, cascaded temperature difference, trigger threshold, ambient temperature, and discharge rate on system performance were investigated. Results show that the coupled cold plate achieves effective synergy between passive and active cooling. Compared to PCM-only system, the coupled system reduces final battery temperature by 9.24 K at 1C (ambient temperature-298 K); relative to single liquid cooling, it extends the time to reach 303 K by 279 s while reducing energy consumption by 38.02% under the same conditions. A low trigger threshold increases cooling frequency and energy consumption, whereas a high value raises maximum temperature by 1.22 K (threshold 1.9 vs. 1.5). A 2 K cascaded temperature difference reduces bottom battery temperature by 1.13 K and increases cumulative latent heat by 11.21% compared to the non-cascaded case. The liquid fraction-feedback strategy exhibits good robustness to ambient temperature (296–302 K), with maximum temperature differences below 0.2 K at discharge end. Under high rates (2C–3C), limited PCM thermal conductivity causes heat accumulation, with temperature rise exceeding 16 K and cumulative latent heat dropping below 20% of total heat. This work provides insights into cascaded PCM-liquid cooling systems for battery thermal management.