Three-dimensional continuous network graphite nanosheets-based carbon foam supported stearic acid as effective shape-stabilized phase change material

A three-dimensional continuous network graphite nanosheets-based carbon foam (CF) was developed by vacuum carbonization of nano-Al2O3/epoxy composites, and employed as support to achieve a shape-stabilized stearic acid (SA)/CF composite phase change material. The influence of preparation temperature of CF on the thermal storage performances of the SA/CF composites was investigated. Results indicate that the nano-Al2O3 can effectively improve the graphitization degree of resulting CF and its compatibility with SA by promoting the growth of graphite nanosheets. The thermal conductivity of SA/CF composite increases with the increasing carbonization temperature of CF. When the carbonization temperature is 1700 °C, the resulting CF (CF-1700) is found as a desirable support for SA. The as-prepared SA/CF-1700 composite has a high thermal conductivity of 3.15 W/mK increasing by nearly 1270 % that of SA, and meanwhile presents a greatly enhanced compressive strength of 6.97 MPa by about 2.13-folds compared with the CF-1700. In addition, the composite with good interfacial bonding exhibits excellent leakage-prevention performance with a high SA loading amount of 77.81 % during the phase change process. In addition, its melting and crystallization enthalpies arrive at 176.6 and 179.7 J/g with an enthalpy efficiency of 82.67 %, respectively. More importantly, the composite displays remarkable chemical stability and thermal storage durability after 200 thermal cycles, revealing great potential in heat storage applications.