A novel three-dimensional network-based stearic acid/graphitized carbon foam composite as high-performance shape-stabilized phase change material for thermal energy storage

Three-dimensional porous carbon materials have received extensive attention as supports for shape-stabilized phase change materials (PCMs). In order to improve the loading capacity, thermal conductivity and encapsulation performance for PCMs, a three-dimensional graphitized carbon foam (GCF) was developed with gradient hierarchical porous surface. The GCF was successfully prepared by pyrolysis of nano-magnesium oxide/epoxy resin mixture followed by surface treatment through a carbon-thermal reaction of Fe2O3. Using the GCF prepared at 1200 degrees C (GCF-1200) as a support for stearic acid (SA), a novel three-dimensional network-based SA/GCF composite was achieved as shape-stabilized PCM. The results show that the GCF-1200 has a large SA loading capacity of 84.66 wt% without any liquid leakage. The prepared SA/GCF-1200 composite exhibits a good interfacial bonding between the GCF-1200 and SA without obvious phase separation in its fracture surface. The composite possesses a high compressive strength of 9.45 MPa increasing by about 3.02-fold compared with the GCF-1200, and meanwhile has a significantly improved thermal conductivity of 1.012 W/m K by 4.36 times that of pristine SA. In addition, the melting and freezing enthalpy for the composite was measured as 181.8 and 182.7 J/g, respectively, which corresponds to a thermal storage efficiency of up to 99.9%. More importantly, it presents excellent thermal reliability and chemical stability without evident changes in enthalpy after 200 thermal cycles. Therefore, the composite has a great potential for thermal energy storage applications.

Automated summary

Three-dimensional porous carbon materials have been developed as supports for phase change materials, showing improved loading capacity, thermal conductivity, and encapsulation performance. The prepared composite exhibits significantly enhanced thermal conductivity and compressive strength, with potential applications in thermal energy storage.