MXene based flexible composite phase change material with shape memory, self-healing and flame retardant for thermal management

Paraffin-based composite phase change materials used for thermal management of electronic devices generally suffers the defects of strong rigidity, low thermal conductivity and flammability. Herein, a flexible and flame retardant composite phase change material (CPCM) of paraffin (PA)/olefin block copolymer (OBC)/MXene is prepared to conduct efficient and safe thermal management. The polymer network of OBC and the layered porous structure of MXene achieve double coupling encapsulation of PA, so PA/OBC/MXene CPCM shows superior thermal stability and high relative enthalpy efficiency (≥97%). Benefiting from phase separation structure of OBC and the photo-thermal conversion capability of MXene, the thermal sensitive flexible CPCM exhibits thermal/light driven shape memory property and self-healing efficiency of 89.60%. The MXene can enhance thermal conductivity of CPCM above 2.3 times that of PA to facilitate rapid heat transfer and dissipation, and the average solar cell temperatures without thermal management and using PA and PA/OBC/MXene as thermal management material are 64.7 °C, 53.5 °C and 47.5 °C, respectively. Moreover, the MXene notably enhances the flame retardancy of CPCM, which can self-extinguish within 12 s. In general, present flexible composite phase change materials achieves higher thermal conductivity, shape adaptation and fire retardancy properties, and those have promising applications in thermal management with rapid heat dispersion and safe operation.