Advancements in Composite Phase Change Materials for Enhanced Thermal Energy Storage Applications

Balancing energy supply and demand remains a significant challenge in the current global landscape, underscoring the growing necessity for effective energy storage solutions. Phase Change Materials (PCMs), such as Paraffin Wax (PW), offer latent heat storage, a key component in advancing renewable energy sources. PCMs are increasingly recognized for their crucial role in enhancing renewable energy systems. Paraffin, a widely studied PCM, offers several desirable thermal properties, including high latent heat capacity, low supercooling, minimal vapor pressure, chemical stability, and an inherent tendency for self-nucleation. Despite these advantages, paraffins low thermal conductivity limits its thermal performance and broader application potential. This study aims to address the limitations of paraffin wax by incorporating varying concentrations of Expanded Graphite (EG) specifically, 3 wt%, 5 wt%, 7 wt%, and 9 wt%. The objective is to determine the effect of EG addition on the thermal characteristics of the resulting composite phase change material (CPCM). SEM, XRD, and FTIR were used to confirm the homogenous dispersion of EG within the PCM matrix. Differential Scanning Calorimetry (DSC) study revealed that adding EG raises both the melting temperature and the latent heat of the CPCM. Furthermore, Thermogravimetric Analysis (TGA) showed an increase in degradation temperature with the addition of EG, indicating increased thermal stability of the composite material. Major Findings: The inclusion of 7% optimized Expanded Graphite (EG) in paraffin wax leads to a remarkable 153% improvement in its thermal conductivity. Despite the addition of EG, the composite retains a substantial latent heat capacity, ensuring its effectiveness as a thermal energy storage material.