Application potential of graphene aerogel in paraffin phase change composites: Experimental study and guidance based on numerical simulation

The current challenge for the application of organic phase change materials is to compromise the conflicting influence of high thermal conductivity matrix content on the heat storage performance and thermal conductivity of phase change composites. Herein, we prepared graphene aerogel (GA) and GA-based paraffin phase change composite (GAP) by the widely reported hydrothermal method and studied the application potential of GA in GAP. The underlying mechanism of paraffin latent heat enhancement caused by GA was discussed from the perspective of the crystallization and phase change process of paraffin. X-ray diffraction and differential scanning calorimetry results showed that as the GA content increased, the paraffin in GAP had an increased crystallinity and exhibited increased latent heat. Activation energy of paraffin's phase change process calculated according to Kissinger model was effectively reduced when GA content was greater than 7.3 wt%, implying a considerable increase in the thermal response rate of GAP. In addition, in order to improve the thermal conductivity enhancement efficiency of GA, thermal conductivity of GAP was predicted by finite element numerical simulation. A good agreement was observed between the experimental and numerical results and some practical suggestions were made for the experimental preparation process.