Dual-encapsulated phase change composites with hierarchical MXene-graphene monoliths in graphene foam for high-efficiency thermal management and electromagnetic interference shielding

Multifunctional phase change materials (PCMs) simultaneously combining high-efficiency thermal management and electromagnetic interference (EMI) shielding performance are urgently desirable yet highly challenging for miniaturized and integrated electronics. Herein, an innovative polyethylene glycol (PEG) composite is developed based on a dual-encapsulation design of vertically aligned MXene-graphene monoliths in graphene foam (MGGF hybrid aerogel). The MXene-graphene monoliths are first incorporated with reticulated graphene foam via unidirectional freezing to construct a hybridized semi-interpenetrated framework, followed by thermal annealing and encapsulating molten PEG, synchronously forming orientational-interlinked thermal pathways in PCM matrix. Impressively, the resultant MGGF/PEG composite achieves a high through-plane thermal conductivity of 11.39 W m−1 K−1 and excellent EMI shielding effectiveness of ∼56.6 dB, as well as desirable latent heat density up to 160.3 J g−1, leakage-proof ability, and superior thermal reliability. Additionally, the MGGF/PEG-based device is demonstrated for thermal energy management toward versatile demands in electronics cooling and solar-thermoelectric conversion. This work sheds new light on designing multifunctional composite PCMs and raises tremendous application prospects for electronic thermal management and solar energy utilization.