Hexagonal boron nitride-based composite PCM for battery thermal management given fast charging/discharging applications

The rapid development of lithium-ion batteries (LIBs) revolutionizes energy storage and facilitates the widespread adoption of renewable energy sources and electric vehicles. However, the performance, lifespan, and safety of LIBs are significantly impacted by their operating temperature, especially during fast charging/discharging. This study investigates the use of hexagonal boron nitride (h-BN) in a composite phase change material (CPCM) consisting of paraffin (PA) and expanded graphite (EG) to enhance battery thermal management systems during fast charging/discharging cycles. The h-BN-based CPCM is characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). This research explores different proportions of h-BN in CPCM and assesses their impact on thermal management efficiency at various charge/discharge rates. Results show that adding h-BN to the CPCM significantly improves thermal conductivity and stability, facilitating efficient heat dissipation and temperature control under rapid cycling conditions. At a 5C discharge rate, the maximum temperature of the battery module decreases from 58.8 °C to 45.6 °C using the optimal CPCM with 8% h-BN, demonstrating the superior thermal performance of the proposed system. These insights advance thermal management strategies by leveraging the unique properties of h-BN, enhancing both battery performance and safety.