Model-driven design and experimental validation of composite PCM for high-rate battery thermal management

Under high-rate discharge, lithium-ion batteries (LiBs) are prone to severe temperature rise and thermal runaway, necessitating effective thermal management. Conventional active thermal management strategies consume substantial energy to maintain constant system temperature. In this study, a passive temperature control method is proposed for LiBs under high-rate discharge conditions. Numerical simulations and experimental investigations were conducted to validate the effectiveness of this method in regulating battery module temperature. Under 3C discharge conditions, the proposed method reduced the maximum module temperature to 35.49 °C, achieving a 60.8 % decrease compared to the module without thermal management. The temperature difference within the module was only 2.69 °C. Furthermore, the thermal management performance of different carbon-based composite phase change materials (PCMs) for the battery system was investigated. Optimal thermal management performance was achieved using a composite PCM (c-PCM) with a phase change temperature of 33.54℃, thermal conductivity of 6.82 W·m −1 ·K −1 , and latent heat of 222.33 J/g. Finally, an Ei@8 %EG c-PCM was fabricated experimentally, and the effectiveness of its thermal management performance was verified. The proposed passive thermal management approach offers significant application value for microgrid energy storage systems based on renewable energy sources by reducing the parasitic energy consumption associated with active thermal management methods.