High thermal conductivity and low leakage phase change materials filled with three-dimensional carbon fiber network

As one of the most effective energy storage compounds, phase change materials (PCMS) play an important role in energy conservation and storage. However, the inherent poor thermal conductivity and liquid leakage of PCMS seriously limit their practical application. Polyethylene glycol·calcium chloride (PEG·CaCl2) phase change materials filled with three-dimensional carbon fiber network were prepared by liquid phase impregnation and hot pressing molding method. The experimental results show that carbon fiber network (CF felt) and PEG·CaCl2 complex structure increase the thermal conductivity and stability. The in-plane thermal conductivity of PEG·CaCl2/CF composite (47.73% carbon content) is 0.97 W/mK, about 103% higher than that of PEG. PEG·CaCl2/CF composite does not present leakage even heating at 80 °C for 45 min (35 °C higher than the melting point of pure PEG), showing low leakage ability. High thermal conductivity, low leakage and low density of this composite suggest a promising route for thermal storage applications.