| Abstract: |
Lithium-ion battery packs generate substantial Joule and entropic heat during fast charging and high-rate discharging, and their performance, cycle life and safety all deteriorate once the preferred operating window of roughly 15–45 °C with a cell-to-cell temperature spread below 5 K is exceeded. Hybrid thermal management that couples phase change material (PCM) storage with liquid-cooled cold plates has emerged as one of the most promising architectures because it combines the temperature uniformity and transient buffering of passive storage with the sustained heat-rejection capacity of active cooling. This paper presents a review and meta-analysis of computational and experimental characterization studies of hybrid PCM–liquid cooling systems for lithium-ion packs. Thirty studies published between 2002 and 2025 are surveyed, covering material selection, cold-plate and channel geometry, PCM encapsulation, control strategy and pack-level integration. A random-effects meta-analysis of forty-eight harmonised hybrid-versus-liquid observations indicates pooled reductions of 6.8 K in peak pack temperature and 2.4 K in cell-to-cell temperature difference, together with a reduction of up to 48 % in parasitic pumping power, at the cost of an average 9 % mass penalty; the benefit is amplified above 2C discharge and above 35 °C ambient. Computational work is dominated by conjugate CFD with enthalpy–porosity phase-change treatment, whereas experimental studies rarely report uncertainty budgets or long-term cycling. Critical analysis identifies non-standard reporting metrics, weak validation practice and unresolved questions of mass penalty and PCM degradation as the main barriers to design convergence. A research roadmap emphasising standardised benchmarking, multiphysics model validation and life-cycle-aware design is proposed. |
