Multi-modal heat rechargeable phase change composites based on MXene coated core-sheath fiber strategy

In order to maintain the human body temperature within a comfortable range in harsh environments, flexible and wearable thermal management fabrics that can combine energy storage and multi-modal heat recharging ability are urgently needed. Here, a strategy of coaxial electrospinning and spray coating was proposed to prepare the MXene-coated core-sheath phase change fibers to satisfy the above requirement. The hierarchical structure endows the composite film with phase change energy storage and photo/electro-thermal multi-modal heat charging performance. Specifically, the encapsulated paraffin wax (PW) in flexible polyurethane (PU) fibers has a high enthalpy value of 91.7 J/g, meanwhile, the flexible film exhibits excellent photo-thermal performance conversion capability (up to 40 °C under the irradiation intensity of 30 mW/cm 2 ) and electro-thermal conversion capability (up to 40 °C at the voltage of 1.5 V) at extremely low MXene loading (0.23 mg cm −2 ), which endows the MXene/PU@PW (MPP) ability of “heat recharging” by low light power density or low voltage. The multifunctional fabrics with phase change function and multi-modal heat recharging capacity exhibit great potential application in the design of wearable personal thermal management.