Synthesis and Characterization of Paraffin Wax‐Based Composite Phase Change Materials With Improved Thermal Properties for E‐Vehicle BTMS

ABSTRACT Phase change materials (PCMs) are increasingly essential in thermal energy storage (TES) systems (TES) because of their excellent energy storage density per unit volume, particularly in low‐ and medium‐temperature applications. This investigation focuses on the improvement of advanced composite phase change materials (CPCMs) by integrating 20 wt% carbon quantum dots (CQDs) into paraffin wax (PW) to increase thermal conductivity. The CPCMs were synthesized using the ultra‐sonication technique. The microstructural morphology of the PCMs and CPCMs was characterized using scanning electron microscopy (SEM). Thermal conductivity measurements were conducted using a Heat Flow Meter, while latent heat and melting temperature were determined through differential scanning calorimetry (DSC). The findings revealed an important enhancement in thermal conductivity with the addition of CQDs mixed with PCM matrix. Specifically, the addition of 20 wt% CQDs into PW increased the thermal conductivity to 0.452 W/m K and enhanced the latent heat by 10.4%. Furthermore, the CPCMs exhibited a larger and higher melting temperature range compared to conventional PCMs, highlighting their improved thermal performance.