Phase Change Material-Coupled Operation Condition Adaptive Liquid-Cooling Strategy for Energy Storage Battery Thermal Management

Thermal management is important for ensuring the safety and reliability of energy storage batteries. Conventional single-mode cooling methods fail to maintain efficiency and temperature uniformity under variable operating conditions. This study presents a phase change material (PCM)-coupled liquid-cooling strategy with an operation condition adaptive control scheme for large-capacity energy storage batteries. A battery management system numerical model with paraffin/expanded composite PCM and a parallel-channel liquid cold plate was developed. The thermal management performance of this system was comprehensively validated under different coolant flow rates, inlet temperatures, PCM melting points, and latent heats, followed by a quantitative sensitivity analysis to identify dominant influencing factors. Based on the parametric analysis, an adaptive cooling strategy was proposed: passive PCM cooling is adopted at low charge/discharge rates, while a delayed liquid-cooling activation strategy is implemented at a high rate to fully use PCM latent heat and reduce energy consumption. Results denote that this system reduces the battery surface maximum temperature by 5.1 °C and the maximum temperature difference by 2.62 °C compared with liquid cooling alone. The coolant flow rate exerts the greatest influence on both the temperature difference and the maximum temperature through the sensitivity analysis, followed by the PCM melting point, coolant temperature, and latent heat. Under the delayed cooling strategy, the total liquid-cooling runtime during continuous operation is reduced by 1720 s, with the number of cooling cycles decreasing from eight to three. This work provides an engineering-based, operation-adaptive thermal management solution that significantly enhances the temperature control effectiveness, energy efficiency, and operational safety of energy storage power stations under real-world variable working conditions.