Multifunctional Polymer Composite Phase Change material with Efficient Thermal Management and Electromagnetic Shielding Properties

The ongoing advancement of electronic devices toward miniaturization and high power density has made efficient thermal management a critical technological challenge. Phase change materials (PCMs) demonstrate significant potential in this field due to their high latent heat capacity. In this study, a three-dimensional porous aerogel was fabricated using polyethylene oxide (PEO) as a polymer matrix and MXene as a conductive filler via an ice-templating method. Polyethylene glycol (PEG) was then incorporated as the phase-change component through vacuum impregnation, successfully yielding a PEG@MXene/PEO composite phase-change material. This structure effectively prevents PEG leakage during phase transition, achieving a composite PEG loading exceeding 98%. Notably, the PEG@MXene/(5%PEO) composite exhibits a leakage rate as low as 3.90% while possessing a thermal conductivity 1.47 times that of pure PEG. In photothermal conversion tests, the material achieved an efficiency of 92.1% under an optical density of 130 mW/cm 2 . When applied to 18650 lithium-ion battery thermal management, the cells coated with the composite maintained significantly lower operating temperatures than untreated cells during cycling at 0.5 C, 1 C, and 2 C rates. Furthermore, the conductive MXene network endowed the PEG@MXene/(1%PEO) composite with an electromagnetic interference (EMI) shielding effectiveness of 30.16 dB. This work presents a novel strategy for developing multifunctional polymer composites that integrate efficient thermal management with electromagnetic protection.