Novel flexible polyurethane/MXene composites with sensitive solar thermal energy storage behavior

In this study, the novel flexible polyurethane/MXene solid-solid phase change materials (SSPCMs) with improved solar-to-thermal conversion efficiency and mechanical strength were constructed using polyethylene glycol (PEG)/MXene blends and hexamethylene diisocyanate trimer (HDIT) through an efficient polyurethane reaction. The obtained SSPCMs exhibit leakage-proof properties, which can be attributed to the formed threedimensional crosslinking network by HDIT and PEG. The melting phase transition enthalpy and relative enthalpy efficiency of SSPCMs with 2.0 wt% MXene (2.0-MPH) are 127.97 J/g and 76.96%, respectively, moreover, its solar-to-thermal conversion efficiency (0) is as high as 90.45%. After 200 times thermal cycling and 50 times light cycling, its enthalpy values and 0 value remained almost unchanged, indicating that the obtained 2.0-MPH possessed excellent solar-to-thermal reliability and cycle reusability. Simultaneously, the great comprehensive mechanical properties have further broadened the application of SSPCMs in the field of solar thermal energy storage.

Automated summary

The study developed flexible polyurethane/MXene solid-solid phase change materials with improved solar-to-thermal conversion efficiency and mechanical strength. The materials exhibited leakage-proof properties and excellent stability after thermal and light cycling tests, suggesting potential applications in solar thermal energy storage.