Thermo-mechanical properties of a novel carbon fiber modified self-encapsulated PEG/sulphoaluminate cement-based thermal energy storage composite

Abstract

In order to synergistically enhance the thermo-mechanical properties of cement-based thermal energy storage composites (TESC), a novel carbon fiber modified self-encapsulated PEG/sulphoaluminate cement-based thermal energy storage composite (CF-PSTESC) was developed using polyethylene glycol (PEG), sulphoaluminate (SAC) and carbon fiber (CF) as the phase change material (PCM), matrix material and modified material separately in this study. The thermal and mechanical performances of CF-PSTESC and their coupling effects were investigated and analyzed using differential scanning calorimetry, mechanical strength test, transient planar heat source method and microstructural analysis. The results show that PEG can be effectively encapsulated in the hydration products of SAC, but it will change the phase change temperature of PEG somewhat. Moreover, the thermal conductivity of CF-PSTESC improved as the CF content grew, which improved by 4.1% and 15.1% at 10 °C and 30 °C, separately, at a CF content of 1.00 wt%. Furthermore, the introduction of CF showed a remarkable influence on the mechanical strength enhancement of CF-PSTESC as confirmed by the experimental results. The compressive strength and flexural strength of CF-PSTESC were increased by 64.9% and 65.7%, separately, when the CF content was 1.00 wt%. Based on the above research results, the CF-PSTESC prepared in this study is a promising TESC.